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AN ESSAY

ON

CALCAREOUS MANURES;

BY

EDMUND RUFEIN,

A PRACTICAL FARMER OF VIRGINIA FROM 1812 ; FOUNDER AND SOLE EDITOR
OF THE farmers' REGISTER; MEMBER AND SECRETARY OF THE FORMER
STATE BOARD OP AGRICULTURE; FORMERLY AGRICULTURAL SUR-
VEYOR OF THE STATE OF SOUTH CAROLINA J AND PRESIDENT
OF THE VIRGINIA STATE AGRICULTURAL SOCIETY.

FIFTH EDITION:
AMENDED AND ENLARaED.

J. W. RANDOLPH,
121, Main Street, Richmond, Va.

1852.

lis

Entered according to Act of Congress in tlxe year 1852,

BY J. W. KANDOLPH.

In the Clerk's Office of the District Court in and for the Eastern Dist. of "Virginia*

PRINTED BY C. H. WYNNE, RICHMOND.

PKEFACE TO THE FIFTH EDITION.

The publication of another edition of this Essay was not
designed to be made during the life of the author, until recent
circumstances served to induce a change of purpose. "When
closing my publication of the ^^ Farmers' Register" — -to which
service I had devoted and (in reference to my own interest) sacri-
ficed the ten best years of my life — I had withdraAvn from all
connexion with the public, and had no thought of again leaving
the quiet seclusion which I had sought and found. But though
not expecting again to appear in print during my life, it was
nevertheless my practice to make corrections of this Essay, and to
prepare materials for future emendations and additions, as new
lights were afforded by extended observation and investigation, or
by my still extending practical experience. This labour was due
to my own reputation. Further, I trusted that, when the results
should finally be offered to my countrymen, this and also other
previous services might be the more justly appreciated, because
the author would then be beyond the reach of applause or recom-
pense. Thus, at different and irregular times, separated by long
intervals of cessation of this particular labour, this edition was
prepared for posthumous publication. And though the publication
is now advanced in time, the before-designed form and manner
are not changed, except in the making of still later additions and
corrections.

Under all the existing circumstances, I trust it will not be
deemed improper, or offensively egotistical, for me, at this time
and in plain words, to assert my just claim to the most important
of the truths which were first announced in the earliest and also
in every subsequent edition of this Essay; and which truths,
though having formerly no other support than my obscure name,
are now so generally accepted and recognised, that they may seem
to have been long established and undisputed. Among these
opinions, or facts, which I was the first to distinctly assert, and to
maintain at length by proof and argument, were the following : —

1. The capacity of impoverished soils for receiving improve-
ment from putrescent manures, being in proportion to their origi-
nal or natural measures of fertility ; and that soils naturally poor
(especially in this country) could not be enriched by these manures,
durably or profitably, above their natural degree of productive-
ness.

2. The almost universal and total absence of carhonate of lime
in the soils of the Atlantic slope of Virginia, and (by mfercnce)
of most others of the United States — and even in most lime-stone

678992

IV PREFACE TO THE FIFTH EDITION.

soils — wliilc, from all existing testimony of preceding writers on
agriculture, the very general, if not universal prevalence of carbo-
nate of lime would have been inferred by every reader.

3. The general presence of some vegetable acid in all our natu-
rally poor soils, and this acid acting as a cause of sterility.

4. The application of carbonate of lime to soils deficient in that
necessary element, serving to neutralize the acid — and, by that and
other stated and important operations or effects, serving to fit the
before poor and unimprovable soils for speedy and profitable
improvement.

These positions were assumed and maintained in all the different
editions of this essay, from 1821 to 1842.* For my own practice
they served, as soon as impressed on my mind, to direct and
enjoin, as indispensable for any important and remunerating im-
provement of poor soils, the application of calcareous manures;
and especially of the cheapest and most abundant resources in this
region, the beds of fossil-sliells (or marl), then scarcely noticed,
and not used in any known practice.

My just claim to the actual introduction in this country of this
now wide-spread and most beneficial means for fertilization, and
my making generally known the value, and inducing the later
numerous and extensive applications by many other farmers, has
not been openly disputed. Detractors in wish and intention have
indeed thought that they had plucked from me some borrowed
plumes, when stating that numerous older writers (in Europe) had
recommended marling — that thousands of farmers in Europe had
thus improved land — and that, even in this country, some few
persons had tried disintegrated fossil shells as manure, and, in still
fewer cases, with success. Such facts, as to European opinions
and practice, have been long and well known to all reading
farmers ; and it would have been impossible, if I had desired it,
to shut out this information. The trials in America were so
limited, and so little known (and of which but one case had then
appeared in print, and that later than my earliest practice, in 1818),
that not one of them had reached me until after my opinions had
been formed and uttered, and my practice, founded thereupon, had
been commenced and was in progress. And when these cases were
subsequently heard of, I industriously sought to gather the facts ;
and have published them all, at length, in the former editions of this
work. But, in truth, none of these prior practices, or opinions

* The principal and more important of these opinions had been asserted
as early as 1818, in a communication to tlie Prince George Agi'icultural
Society. But as that communication (which was the first concise sketch,
since enlarged to this Essay) was not then printed, perhaps I may have no
right to cite it as showing so early a date for my claims of discovery. An
extract from that communication w^iil be embraced in one of the pieces in
the Appendix.

PREFACE TO THE FIFTH EDITION. V

connected therewith, had any bearing on my claim — which is of
showing why, and under what circumstances, calcareous manures
are especially and generally necessary in this country, and of in-
ducing the extensive use of the particular material above named,
of which the existence had before attracted the notice of but few
persons, and of which any value was suspected by still fewer — and
the few earlier trials of which had been altogether empirical, and
made without any knowledge of the mode of operation — and which
therefore had generally ended in supposed failure and certain dis-
appointment, and speedy abandonment of all further effort.

As to the opinions above enumerated, which served to direct
my practice from the beginning of 1818, they had either no sup-
port from previous authority, or, if asserted by any, had been
denied by higher authority and by general understanding. This
latter case, of feeble assertion and stronger denial, covers only the
doctrine of acid in soils. The other important positions had not
been asserted by any known authority, previous to my declaration.
Yet all these doctrines are now received either generally or uni-
versally, and so appear in recent publications on scientific agricul-
ture. And in regard to the existence of acid in soil, the actual
discovery was truly made in Europe, later, indeed, than my first
annunciation of the doctrine, by men of high scientific attainments,
who most proba4)ly had never even heard of the opinions of so
remote and obscure a writer as myself.

Under these circumstances, when these now generally received
opinions are seen stated in any of my former editions (and still more
if in a subsequent edition), such appearance would not necessarily
imply the originality of such opinions. For it might well be
inferred by the (otherwise well-informed) reader, that these doc-
trines had been introduced in the later editions, after they had
been discovered and published by other authorities. For it is the
general and proper usage of authors of scientific and didactic
works, to add to each successive edition any new lights on the
subject, up to the latest time of publication. Hence, when dates
and authorities are omitted (in regard to doctrines long established
and received), it is left doubtful which of the positions of an
author's latest edition had also been maintained in his earliest ;
and also, whether such doctrines were original with the author
then stating them, or belonged to some other discoverer not then
cited. It is especially designed, in this last edition, to avoid every
such source of error. For this purpose, the Chapters (from II. to
VIII. inclusive) which will set forth all these theoretical doctrines,
^vill exhibit an exact reprint of the edition of 1832. No altera-
tions of the original text will be made, other than merely verbal
and immaterial corrections. Any new matter, or extension of
remark or illustration, will be designated in every case; and,
1*

Vi PREFACE TO THE EDITION Or 1832.

however since ampliified in expression or varied in form, these
same positions, more concisely worded, were all embraced in the
earlier edition of 1821 (in the " American Farmer'^), and, as was
before stated, the main points of these opinions were also set forth
in the earlier communication of 1818. E. R.

Marlbourne, Hanover, Va., August, 1852.

PREFACE TO THE EDITION OF 1832.

,The object of this Essay is to investigate the peculiar features and
qualities of the soils of our tide-water district, to shoAV the causes of tlieir
general unproductiveness, and to point out means, as yet but little used,
for their effectual and profitable improvement. My observations are par-
ticularly addressed to the cultivators of that part of Virginia which lies
between the sea eoast and the falls of the rivers, and are generally in-
tended to be applied only within those limits. By thus confining the appli-
cation of the opinions which will be maintained, it is not intended to deny
the propriety of their being farther extended. On the contrary, I do not
doubt that they may coiTectly apply to all similar soils, under similar cir-
cumstances ; for the operations of Nature are directed by uniform laws,
and like causes must everywhere produce like eflFects. But as I shall rely
for proofs on such facts as are either sufficiently well known already, or
may easily be tested by any inquirer, I do not choose to extend my ground
60 far as to be opposed by the assertion of other facts, the truth of which
can neither be established nor Overthrown by any available or sufticient
testimony.

The peculiar qualities of our soils have been little noticed, and the causes
of those peculiarities have never been sought ; and though new and valua-
ble truths may await the first explorers of this opening for agricultural
research, yet they can scarcely avoid mistakes sufficiently numerous to
moderate the triumph of success. I am not blind to the difficulties of the
investigation, nor to my own unfitness to overcome them ; nor should I
Lave hazarded the attempt, but for the belief that such an investigation is
all-important for the improvement of our soil and agriculture, and that it
was in vain to hope that it would be undertaken by those who were better
qualified to do justice to the subject. I ask a deliberate hearing, and a
strict scrutiny of my opinions, from those most interested in their truth.
If a change, in most of our lands, from hopeless sterility to a high state
of productiveness, is a vain fancy, it will be easy to discover and expose
the fallacy of my views ; but if these views are well founded, none deserve
better the attention of farmers, and nothing can more seriously affect the
future agricultural prosperity of our country. No where ought such im-
provements to be more highly valued, or more eagerly sought, than among
us, where so many causes have concurred to reduce our products, and tho
prices of our lands, to the lowest state, and are yearly extending want, and
its consequence, ignorance, among the cultivators and proprietors.

In pursuing this inquiry, it will be necessary to show the truth of vari-
ous facts and opinions which as yet are unsupported by authority, and
most of which have scarcely been noticed by agricultural writers, unless to
be denied. The number of proofs that will be required, and the discursive
course through which they must be reached, may probably render more

PRErACE TO THE EDITION OP 1832. vii

obscure the reasoning of an unpractised writer. Treatises on agriculture
ouglit to be so wi'itten as to be clearly understood, tliough it should be at
the expense of some other requisites of good writing ; and, in this respect,
I shall be satisfied if I succeed in making my opinions intelligible to every
reader, though many might well dispense with such particular explanations.
Agricultural works are seldom considered as requiring very close attention ;
and therefore, to be made useful, they should be put in a shape suited to
cursory and irregular reading. A truth may be clearly established — but
if its important consequences cannot be regularly deduced for many pages
afterwards, the premises will then probably have been forgotten, so that a
very particular reference to them may be required. These considerations
must serve as my apology for some repetitions — and for minute explana-
tions and details, which some readers may deem unnecessary.

The theoretical opinions supported in this Essay, together with my earliest
experiments with calcareous manures, were published in the "American Far-
mer" (vol. iii. page 313), in 1821. No reason has since induced me to retract
any of the important positions then assumed. But the many imperfections
in that publication, which grew out of my want of experience, made it my
duty, at some future time, to correct its errors, and supply the deficiencies
of proof, fi'om the fruits of subsequent pi'actice and observation. With
these views, this Essay was commenced and finished in 1826. But the
work had so grown on my hands, that instead of being of a size suitable
for insertion in an agricultural journal, it would have filled a volume. The
unwillingness to assume so conspicuous a position as the publication in
that form would have required, and the fear that my work would be more
likely to meet with neglect or censure than applause, induced me to lay it
aside, and to give up all intention of publication. Since that time, the use
of fossil shells as manure has greatly increased, in my own neighbourhood
and elsewhere, and has been attended generally with all the improvement
and profit that was expected. But from paying no regard to the theory of
the operation of this manure, and from not taking warning from the
errors and losses of myself as well as othei's, most persons have operated in-
judiciously, and have damaged more or less of their lands. So many dis-
asters of this kind seemed likely to restrain the use of this valuable ma-
nure, and even to destroy its reputation, just as it was beginning rapidly
to be extended. This additional consideration has at last induced me to
risk the publication of this Essay. The experience of five more years,
since it was written, has not contradicted anj' of the opinions then ad-
vanced— and no change has been made in the work, except in form, and by
continuing the reports of experiments to the present time.

It should be remembered that my attempt to convey instruction is con-
fined to a single means of improving our lands, and increasing our profits ;
and though many other operations are, from necessity, incidentally noticed,
my opinions or practices on such subjects are not referred to as furnishing
rules for good husbandry. In using ©alcareous manure for the improve-
ment of poor soils, my labours have been highly successful ; but that suc-
cess is not necessarily accompanied by general good management and
economy. To those who know me iutimatelj', it would be unnecessary to
confess the small pretensions that I have to the character of a good farmer ;
but to others it may be required, for the purpose of explaining why other
improvements and practices of good husbandry have not more aided, and
kept pace with, the efi'ects of my use of calcareous manures. E. B,

Frince George county, Virginia, January 20th, 1832.

Tlii PREFACE TO THE EDITION OF 1836.

* EXTRACTS FROM THE

PREFACE TO THE EDITION OF 1835.

When the preceding edition of this Essay was published, it met with a re-
ception fai' more favourable, and a demand from purchasers much greater,
than the author's anticipations had reached ; and it is merely in accordance
with the concurrent testimony of the many agriculturists who have since
expressed and published opinions on the subject, to say that the publication
has already had great and valuable effects in directing attention, and in-
ducing successful efforts, to the improvement of land by calcareous ma-
nures. Experimental knowledge on this head has probably been more than
doubled within the last two years ; and the narrow limits of the region
within which marling had previously been confined, have been enlarged to
perhaps ten-fold their former extent. Still, the circumstances now existing,
however changed for the better, present a mere beginning of the immense
and valuable improvements of soil, and increase of profits, that must here-
after grow out of the use of calcareous manures, if their operation is pro-
perly understood by those who apply them. But if used without that know-
ledge, their great value will certainly not be found ; and indeed, they will
often cause more loss than profit. It is therefore not so important to the
farmers of our country at large to be convinced of the general and great
value of calcareous manures — and to those in the great Atlantic tide-water
region to know the newly established truth, that their beds of fossil shells
furnish the best and cheapest of manures — as it is, that all should know
in what manner, and by what general laws, these manures operate — how
they produce benefit, and when they may be either worthless or injurious.
And this more important end, the author regrets to believe has as yet
scarcely been even partially attained, by the dissemination and proper un-
derstanding of correct views of the subject. Of course it is not to be sup-
posed that this Essay has been read (if even heard of) by one in ten of the
many who have been prompted by verbal information to attempt the prac-
tice it recommends ; and of those who have read, and who have even ex-
pressed warm approbation of the work, it has seldom been found that their
praise was discriminating, or founded upon a thorough examination of its
reasoning and theoretical views, on which principally rests whatever value
it may possess. For all persons who are so easily convinced, it may truly
be said, that the volume embraced nothing more, and was worth no more,
than would be stated in these few words — "the application of calcareous
manures will be found highly improving and profitable." It is not there-
fore at all strange that the attentive reading of a volume, to obtain this
truth, was generally deemed unnecessary.

Though the previous edition of this work has been nearly exhausted, the
circulation has as yet been almost confined to that small portion of the
state of Virginia alone in which the mode of improvement recommended had
previously been successfully commenced, or had at least attracted much at-
tention. But this district is not better fitted to be thus improved than the
remainder of the great tide-water region stretching from Long Island to
Mobile — and to a great part of which calcareous manures may be cheaply
applied. It is only in parts of Maryland and Virginia that many extensive
and highly profitable applications of fossil shells, or marl, have been j^et
made. In North Carolina the value of the manure has been but lately tried ;
in Soutli Cai'olina and Georgia, no notice of it has yet been taken, or afc
least has yet been made known ; and in Florida and Alabama (parts of
which are peculiarly suited to receive these benefits), it is most erroneously
thought that such improvements are only profitable for long settled and
impoverished countries. ***♦*»

PREFACE TO THE EDITION OF 1842. ix

But though the circulation of this work will be most useful through the
great tide-water region, which is so generally supplied with underlying
beds of fossil shells, and so much of the soil of which especially needs
such manure, still the assertion may be ventured that there is no part of
the country where the views presented, if true, are not important to be
known ; and, if known, would not be highly useful to aid the improvement
of soils. It is to the general theory of the constitution of fertile and
barren soils, that the attention and severe scrutiny of both scientific and
practical agriculturists are invited ; and to the several minor points there
presented, which are either altogether new, or not established by autho-
rity— such as the doctrine of acidity in soils — of the incapacity of poor
and acid soils to be enriched — and of the entire absence of carbonate of
lime in most of the soils of this country.

April, 1835.

■ ' < "■

EXTRACTS FROM THE
PEEFACE TO THE EDITION OF 1842.

In the few years which have passed since the issue of the preceding
edition, it is believed that the use of marl and lime, in lower Virginia, has
been extended over thrice as much land as had been previously thus im-
proved ; and the previous clear income of the farmers thus fertilizing their
lands has probably been already thereby increased in amount by several
hundreds of thousands of dollars, and the intrinsic value' of the lands
raised by as many millions. These great augmentations of annual profits
and of the true value of landed capital, from this single source, if they
could be accurately estimated, would be seen to have produced an important
item of additional revenue to the treasury of the commonwealth. And
these additions of wealth to individuals and to the state, would be obvious
as well as real, but for the existence of other circumstances which have
operated to counteract or to disguise the proper results. The most im-
portant of such influences will be merely referred to here in the cursory
manner only that the occasion permits.

In the first place — besides the deservedly very low appreciation of all
lands in Virginia, founded on the smallness of their products, the market
prices were formerly still more reduced by the almost universal urgent de-
sire of proprietors to sell, that they might be enabled then to emigrate to
the new and rich lands of the west. The impossibility of selling, even at
the lowest valuation price, was the only thing which prevented the actual
flood of emigration being so much more swelled as to leave half our lands
unoccupied and waste. If purchasers had but presented themselves, fully
half the farms in Prince George county (and it is presumed of many other
counties) might have been bought up at a considerable deduction from the
lowest estimated value ; and all the sellers would have removed, with all
their capital, to the western wilderness. To the then actual and regular
flow of emigration from the now marling district, an effectual barrier has
been opposed by the introduction of that mode of improvement. All emi-
gration has ceased wherever by trial of this means the cultivators of the
land found their labours to be richly repaid. Thus, in estimating the gains
of individuals and of the state, on this score, the comparison should be
made, not with the value of property and population which remained
twenty years ago, but with what would have remained now, if the then
existing inducements to emigration had continued to go on and to increase,
as they would have done, with time.

Next — the actual increase of intrinsic value of marled lands is far from
being even yet fully appreciated, because of the generally prevailing and

X PREFACE TO THE EDITION OP 1842.

very erroneous mode of estimating tlie values of the increase of permanent
net income from land, (as -will be made manifest in a part of tliis Essay — )
and but few even of those persons who have obtained such values by marl-
ing their lands, would estimate them at one-fourth of their true amount.
The source of any permanent net increase of only $6 of annual income from
land, adds $100 to the intrinsic value of the land. And this proposition
is not the less true, and to the full extent asserted, even though the esti-
mate of private purchasers and sellers, and of public assessors of lands,
may all count for the market price but a small proportion of the increased
real value.

Next — even whatever of new appreciation the foregoing influences might
have permitted to be exhibited in the increased market price of lands, and
still more their new real value, have been disguised, or altogether concealed,
by the great and frequent fluctuations of all market prices of property,
and by the general misdirections of capital and industry, all caused by the
universal individual and national gambling (whether voluntary or compul-
sory), at the maddening and ruinous game of paper-money banking — to
which system of delusion and fraud this otherwise most blessed country
and fortunate people are indebted for so much of disaster, loss, and, still
worse, of wide-spread corruption of habits and morals. The enormous
apparent and illusory profits promised by this system, and by the stock-
jobbers who alone have fattened upon the facilities it off"ered for fraud and
plunder, served powerfully to depress the market price of lands, and to
discourage agricultural investments and pursuits. For, whatever actual
profits the improvement and cultivation of the soil miglit oft'er to reward
the care and labour of the proprietor, the stocks of various corporations,
falsely appreciated by means of a bloated paper currency, and by the arts
of stockjobbers, promised much higher profits, without requiring either
care, labour, or risk. Thus, the higher that fictitious dividends of profits
or the false values of stocks rose, and the stronger became the induce-
ments to make stock investments, the more the prices of lands sank (com-
paratively) below their true value, because of the general disposition to
convert landed capital to stock capital. But the real and solid increase of
income and of wealth to individuals and to the commonwealth, caused by
the permanent improvement of the soil, is not the less certain, or the less
profitable, because fictitious appreciations of values, caused by the fraudu-
lent banking system, and the consequent speculations and madness of its
votaries and victims, have been both so much higher and lower, at difi"er-
ent times, as to make the amount of actual improved values appear small
in comparison, even if they were not thereby entirely concealed. But
these delusive and ruinous causes of fluctuating prices and values are now
fast showing their emptiness, and vanishing from view ; and whenever the
fraudulent paper system shall be completely exposed and entirely exploded,
then both lands and the paper-money system will be estimated at their true
value. May the consummation be speedy, complete, and final 1

But even though, if properly and accurately estimated, the true value
of the lands already marled and limed in Virginia has been increased to
the amount of millions of dollars, the gain is very small compared to that
which yet remains ready to be obtained. Marling has not yet been
extended over the hundredth part of the surface to which it may be pro-
fitably applied ; and liming, not to the ten-thousandth part of the lands
of the state to which lime may be brought. And elsewhere, with the
exception of a small part of Maryland, the beginnings of marling only
have as yet been made. Nevertheless, these beginnings are the widely-
scattered seeds which will spring up and spread, and hereafter yield
abundant harvests.

December, 1842,

CONTENTS.

Preface to fifth edition . . . . . . . . iii

Preface to earlier editions vi

Chapter I. — Introductory. General description of agricultural earilis
and soils. Physical and chemical constituents of soils.

Difficulties of defining earths and soils, 17, 18. Chemists' definitions unsuitable for agricul-
ture, 18. Agricultural earths, 19. Siliceous earth, 19. Aluminous, 20. Calcareous, 20;
different definitions thereof by authors, 22. Chalk, 23. Magnesian earth, 24. Humus,
25. Soils and sub-soils, 25. Constituents of soils, 26, and of sub-soils, 27. Physical and
chemical constituents, 28, 29, 30. Nomenclature and definitions of soils, 31, 32, 33.

Chap. II. — On the soils and state of agriculture of the Tide-water Dis-
trict of Virginia.

General features of the district and its soils, 34, 36. Ridges, 35. Slopes', 35, 36. River mar-
gins and alluvial lands, 36. Exhausting tillage and small products, 36. Decreasing popu-
lation, 38. Hopeless of improvement under existing circumstances, 39.

Chap. III. — The different capacities of soils for improvement.

Five principal propositions stated for discussion, 39. Natural fertility defined, 40. Perma-
nency of either fertile or sterile character of different countries and soils, 41. Land natu-
rally poor not capable of being enriched by putrescent manures, 41, 42. Opposing opinions
and authorities, 43, 45. Facts in support, 44. The degree of original fertility the limit of
profitable improvement by putrescent manures, 46, 47.

Chap. IV. — Effects of the presence of calcareous earth.

Calcareous earth not found in our poor soils, 48. Its presence indicating great fertility, 48.
Natural growths on shelly and on poor soils, 49. All authority supports the general pro-
eence of carbonate of lime in soils, 50 to 53, Soils rarely calcareous in Virginia, 54. Re-
cent confirming testimony (note), 54, 55.

Chap. V. — Results of chemical examinations of various soils.

Methods for testing the presence or absence of carbonate of lime in soils, 56 to 59. Various
soils tested — calcareous, 69 to 61. All known calcareous soils rich, and no poor soil calcar
reous, 61.

Chap. VI. — Chemical examination of rich soils containing no calcareous

earth.

Rich river lands, 62 — and also mountain lime-stone soils, C3 to 65. Prairie soils of Alabama
generally highly calcareous, or super-calcareous, 66, 67.

Chap. VII. — Proofs of the existence of acid and neutral soils.

Lime in some form present in every soil, 08. Acid not considered an ingredient of soil by
any writers of authority, and denied by others, 69, 70. Proofs of acidity in soil, 70.
Growth of acid plants, 71. Nourished best by dead acid plants, 71, 72. By other putres-
cent manures, 72. Acid poisonous to cultivp.ted plants, 73. Pisaj^pearance of carbonate of
lime in cultivated soils, 75 to SO. Wood ashes contain lime, 81, 82. S<"icntific confirmation
of arid in soil, 82 to 88. Discovery of humic acid, 83 ; its properties, 86. Successive natu-
ral changes of chemical character in soils, 88, 89, 90. Testimony of Loudon of originality
of doctrine (note), 91.

Chap. VIII. — The mode of operation by which calcareous earth increases
the fertility and ^productiveness of soils.

Bilicious and aluminous earths have no chemical power to retain putrescent manure, 92,
93, 94. Calcareous earth has such power, and how, 94, 95. Examples of combining opcrar
tions, 95. Power of fixing fertilizing matters in soils, 96. Power of neutralizing injurious
adds, 97, 98. Power of altering and improving texture of both sandy and clayey soils, 98,

(11)

Xii CONTENT^.

99, and of lessoning evils of too much dryness and moisture, 99. Lime a nece?snry food
for plants, but only within narrow limitation, 100, 101. Proportions of lime in ashes of
Taxious plants, 102.

Chap. IX. — Action of caustic lime as manure.

Dayy's theory of liming stated, 103. Applied to practice, 10-4. Action of caustic lime gene-
rally to le avoided, 104, Lime acts generally as carbonate, 105. form of classification of
manures, 106.

Chap. X. — Introductory and general observations on marl and lime.

Fossil shells, improperly called marl, 107. Incorrect use of t«rms in England, 108-9. Dif-
ferent and general misapplications of the name of '• marl" (note), 109, and of " marling"
(note), 110. "Liming," in practice, equivalent to marling, 110 to 113. Preliminary
remarks on experiments, 114. Oldest applications of marl in Virginia, 114.

Chap. XI. — Experiments tcith, and effects of, calcareous ma?mres on acid
sandy soils, newly cleared.

Experiments stated, and earliest and later results on light and acid loam, recently brought
Hnder cultivation, 116 to 122. Errors in the mode of experimenting stated, 122-4.

Chap. XII. — Effects of calcareous mamtres on acid clay [or stiff) soils
recently cleared.

Description of the peculiar soil operated on, 124. Experiments and results stated, 125 to
129. llemarkable effects on clover and grain crops, 127 to 129.

Chap. XIII. — The effects of calcareous manures on acid soils reduced by

cultivation.

Marling always eflFective on such soils, 130. Experiments stated, and early good results, 130
to 136. Diseased crops of grain caused by excessive marling, 133. Effects of marl with
putrescent manure, 137, 138.

Chap. XIV. — Effects of calcareous manures on ^' free light land.'*

Character of such soil, 139, Experiments, 139, 140.

Chap. XV. — Effects of calcareous manures on exhausted acid soils, under

their second growth of trees.
Experiments of this kind, 141, 142.

Chap. XVI. — Effects of calcareous manures alone, or tvith gypsum, on
calcareous and neutral soils.

Inefficiency of marl on stich soils, 143. Gypseous marl, 144. Experiments, 145 to 147.

Chap. XVII. — Digression to ihe them^y of the action of gypsum as ma-
nure. Supposed cause of its want of power and value on acid soils.

General inefficiency of gypsum on Atlantic coast, and mistaken views as to the cause, 141.
Exceptions on neutral soils, 148. And the true cause of usual inefficiency, 149. Theory
of this inefficiency, and its removal, 151 to 154.

Chap. XVIII. — The damage caused hy too heavy dressings of calcareous
manure, and the remedy.

Earliest effects observed, and symptoms described, 155. Means for preventing or of curing
the injury, 156-7. The disease found only on soils naturally acid, 157; and not caused
merely by excess of calcareous earth, 158, and probably by humate of lime, 159.

Chap. XIX. — Recapitulation and more fidl statements of the effects of
calcareous manures.

The results of marling have conformed to previous theoretical views, 159. Exceptions above
the granite range, and causes, 161. Hazel loam, 161. Effects of calcareous manure pro-
portioned to the organic matter in soil, 162. Marl on "^alls," 163. Prevents the washing
effects by rains, and the moving of sandy soils by winds, 164. Quantities of marl to lie
applied, 166. Effects in preserving vegetable matter from waste, 167. "Free light land,"
and its speedy exhaustion, 168. Marling deepens soils, 169. Gives peculiar valae to sandy
sub-soils, 170. Hastens maturing of crops — cotton — wheat, 170. Strengthens straw of
wheat, 171. Peculiar benefits to leguminous plants, and especially to clover, 172, and to
some bad weeds, 173. Failures of clover ou marled lauds, 173. Effect of calxing in eradicat-
ing acid i)lauts, 174-5.

CONTENTS. * Xii!

Chap. XX. — Directions for tlie use of marl in connexion icith oilier
farming operations.

Usual difficulties of bei^inners without reason, 175. The labovirs to he regular and continu-
ous, 17(3, Necessity for intermixing marl regularly with the soil, 176-7. Manner of drop-
ping and spreading heaps, 177. Organic manure an essential accompaniment, 177, 178;
supplied by vegetable growth of the fields, 178. Ordinaiy farm-made manures, 179 ; other
materials, 180.

Chap. XXI. — Actual improvements and results of marling. Peculiar
value of sandy soils.

Causos of defective results of earliest marling labours, 181-2. Actual results on Cogging
Point farm, to 1842, 183. Crops from 1813 to 1851, 184. Remarks and notes on same,
185-6.' Culture and crops on Marlbourne, 187-8. Causes of neglect of marling, and small
effects, 189. Value of sandy soils, 190. Poor soils of lower Virginia also very shallow, 191.
Rates of increase of products from marling, on different lands, 192.

Chap. XXII. — The extent of duration of the effects of calcareous manures.

Duration of effects known by experience, 192-4. Re-marlings, why required, 195. Question
of duration of calxing, 196. Practice and opinions in Britain, 197, 198. Alleged reasons
for waste of lime in soils, and answers thereto, 199 to 211. Sinking of lime in soil, 211,
212. Effect of organic (or putrescent) manures made permanent by combination with cal-
careous, 214 to 210. Apparent exceptions, 217. Actual duration of effects, 218. Antici-
pated progress of improvement, and fixing of organic matter by calxing, 219 — and of steri-
lity caused, under reverse circumstances, 220.

Chap. XXIII. — General observations on the valuations of lands and their
improvements, and the expenses and profits of marling.

Usual estimates altogether erroneous, 221. True mode of estimating values, 222 to 225.
Supply and demand regulate gelling prices of lands, 227. Injudicious marling labours,
228. General profits, 229.

Chap. XXIV. — Other fertilizing powers and effects of calcareous earth.

Soils of ancient alluvial formation (or latter drift), 230. Effects of calxing thereon, 231 to
233. Action of calx by solvent power, 234. Sterility, when caused by calxing, and how,
235 to 237. Benefit of lenient cropping, 237, and supplying vegetable matter, 238. Erro-
neous practice in South Carolina, 239 to 241. Organic matter in plants, 242 ; how consti-
tuted, 243. Proportions of carbon, hydrogen, oxygen, and azote in plants, 244. Whence
derived, 246 to 248. Supply of carbon from the atmosphere increased on calcareous soil,
248 to 250. Dr. Wight's experiments thereupon, 250 to 252. Other proofs, 253. Azoto
supplied from the atmosphere through leguminous plants, 253 to 257. Their peculiar ma-
niiring effects thus caused, 258. Residue of roots of clover, Ac, 259. Value of the south-
ern field pea (or bean), 261. Recapitulation, 262. Effect of lime in soils and compost
heaps to produce nitrates, 263. This explains some practical results before not understood,
266, 267. Effect of lime in promoting the healthy constitution and vigorous growth of
plants, 267, 268, and the better quality of products, 268.

Chap. XXV. — The use of calcareous earth recommended to preserve
putrescent manures, and to promote cleanliness and health.

Effects of calcareous earth in preventing waste of products of animal matter, 269, 270. Cases
for use of this power, 271 to 274. Unfitness of quick-lime for this purpose, 274. Benefit in
preventing disease, 275, 276. How the burning of towns benefits health, 277. Benefits to
health of calcareous soil in Alabama, 278 — ^in Virginiaj 279 to 281— in France, 281, 283 —
in England, '283.

Chap. XX VI. — The excavation of marl-pits, and carrying out and ap-
plying marl.

Dry and high-lying marl, 284. Wet marl in hilly lands, 285. Method of opening and work-
ing pits of such marl, 286 to 289. Draining the excavation, 289, 290. Deep pitting, 290.
Machines for raising marl, 291 to 295. Making roads, 295. Implements and carts for
marling, 297. Spreading, 298. MarliAg tables and estimates, 299 to 302. Importance of
marling labours being continuous, 303.

Chap, XXVII. — Directions for the searching for and testing of marl.

Searching for marl, 304. Use of the anger, 305. Exposures of marl, 306-7. Extended
labours anticipated, 307. Usual appearances of marl, 308-9. Po.-ntion and character of thq
strata, 309-10. Dii-cctions for analyzing, 310 to 313. Distant trausportation of marl, 313
to 317.

Q

XIV CONTENTS.

Chap. XXVIII. — Estimates oftlie cost of labour applied to marling.

The proper groiande for estimates, 318. Cost of the labour of a negro man, 319 — of boy,
•woman, and girl, 320 ; of working horse and mule, 320 ; costs of carts and implements,
321. These estimates applied to particular operations of marling, 322 to 326.

Chap. XXIX. — Details of actual and extensive marling labours.

Actual labours on low-lying andf wet marl, 327. Marl and accompanying beds described,
328-9. Excavation in email perpendicular pits, 329. Horizontal plan of diggings, 330-31.
Beginning and progress of labour, 329, 333. Work of a single mule, 334 to 339. Esti-
mated cost of the work, and remarks, 336 to 341. Plxcavating marl in large graduated
pits, 342 to 350. Savings of expense before incurred, 351-52. Expenses at various dis-
tances, and rule for estimating, 353. Hazard of large excavations, 354. Quantity of marl
removed, 355.

Chap. XXX. — The progress of marling in Virginia.

Usual obstacles to the progress of all new improvements in agriculture, 356. The beginning
and progress of marling in Virginia, and general condition (in 1842), 357 to 360. Liming,
S60. General effects of the use of calcareovxs manures in Virginia (to 1850), on valuea of
lands and products of taxation, general wealth, and population, 300 to 363.

APPENDIX.

Introductory remarks 363

Note I. — Additional proof, offered in the production and existence of
black waters, of the action of lime in combining vegetable matters with
soil.

Black waters of certain streams and ponds, and absence of colouring matter in others, 363 to
365. Causes, 365. Proofs and illustrations, 366. Clearness of lime-stone water, 367. Facta
and causes of black waters, 368 to 371.

Note II. — The statements of British autJiors on "marl," and their
applications of the name generally incorrect, and often contradictory.

Subject stated, 371-2. CoiTCct definitions of marl, 373. Clay and shell marl, 374. "Marls"
not calcareous, 375-6. Old authors. Marls not known to be calcareous by their describers,
377 to 380. American opinions deduced from English books, 380. Other manures not
valued for their known calcareous parts, 381. Errors of modern writers, 382; Arthur
Young, 382 to 385 ; Lord Kames and Sir John Sinclair, 386. Ca.'^es of English marling not
serving to make soil calcareous, 387-8. Sir John Sinclair confounding the operations of
carbonate, phosphate, and sulphate of lime, 389. Marling of Norfolk, 390. Clays of New
York calcareous, 391. Jlarshall's notices of marl and marling, 391 to 894. Errors of
Farmers' Journal, 395. Fossil sea-shell beds (or marl of Virginia) in Europe, 395. Faluns
and falunage of France, 397-8. Oldest and English views of the marl (now so called) of
Vu-g"inia, 399. Deductions, 399, 400. Marl and marling of the ancients — notices by Varro
and Pliny, 401-2.

Note III. — The earliest known successful applications of fossil shells as

manure.

Oldest applications unsuccessful, 403-4. First successful use in Virginia, 405, and in Mary-
land, 405. John Taylor's slighting opinion, 406. Marling of John Singleton, 406 to 408.

Note IV. — First views which led to marling in Prince George county.

The author's early lessons and opinions, and errors in farming, 410-11. Former condition
of his land, and sources of opinions, 412. Taylor's and Davy's doctrines, 413. Acid in
soils supposed, 414-15. First effort in marling. 416, and first results, 417. Earliest opinions
of constitution of soils, 418 to 420. P^nglish views and writings opposing the use of our
marl, 421. "Iluffin's Folly" and first operation Ui example, 422-3. Succeeding labours,
423-4. Damage caused by marling, 424 to 426.

Note V. — Description and account of the different kinds of marl, and
of the gypseous earth of the tide-water region of Virginia.

Need for the information to be offered, 427. Character, constitution, and formation of true
• marl, 428 to 430. Classification of mai-ls, 431. Chalk and rotten lime-stone, 432, Travertin,

CONTENTS. XV

433. Argillo-calcareous, or true marl, 433. Shell-pand, 434. Shell marl, as tmderstood in
Britain, 434-5. Tertiary fossil shell marl (in Virginia), 435-6. Miocene marl, 437 to 440.
Varieties, 441 to 448. Crystallization in marl, 443-4. Loss of calcareous parts of marl, 448.
Comparative values, 449. Eocene marl, 450 ; of Coggins Point, 450-1. Extent of same kind,
452. Qualities, 453. Other eocene marls, 454. Gypseous earth, 454. Gypseous earth of Jamea
river, 455 to 475. Green-sand, 458. Use of gypseous earth as manure, 459. Sulphuret of iron
(and gypsum) contained, 460. The various strata at Evergreen, 462 to 464. At Coggins
Point, 465 to 467. Harrison's Bar of gypseous earth, 467. Green-sand of New Jersey, 468.
Analyses of green-sands of Europe and America, 469-70. Analyses of gypseous earth of
Coggins Point, 471 to 473. Gypsum the main operating ingredient, 474. Eocene green-
Band (or gypseous) marl of Pamunkey, 475 to 482. Different layers described, 476 to 479.
Olive earth, 479-80. Gypseous earth of Pamunkey, 481-2. All appreciable effects due, not
to green-sand, but to gypsum, 482. Position and order of succession of the different layers
of the Pamunkey eocene, 483 to 485. Sulphiiret of iron in gypseous earth and some marls,
486-7. Alleged existence of green-sand, in quantity, in ordinary miocene marls, 487-8.
Tlie a.ssertion disproved, 489 to 491. Peculiar miocene. of Hampstcad bed only, known to
contain green-sand in confiiderable proportion, 491 to 493.

AN ESSAY

ON

CALCAREOUS MAJEURES.

CHAPTER I.— Introductory.

GENERAL DESCRIPTION OP AGRICULTURAL EARTHS AND SOILS. — '
PHYSICAL AND CHEMICAL CONSTITUENTS OF SOILS.

In discussions or instructions upon the fertilization of land, it
is an important requisite that we should correctly distinguish be-
tween earths and soils, and the many varieties of the latter com-
pound bodies. Yet the terms used for this purpose, are generally
misapplied ; and even among writers of high reputation and autho-
rity, no two agree in their definitions of soils, or modes of classifi-
cation. That such differences of definition, and contradiction of
terms, should exist, will appear the less strange, and the resulting
errors the more excusable, to those readers who have nrost care-
fully studied this branch of agricultural science, and who, therefore,
can best appreciate the difficulties of the required classification.
Each writer on soils is compelled to use terms in senses different
from the greater number of his many predecessors ; because but
few of them have concurred in even the most important definitions.
Where such great difi"erenccs exist, and where no one known plan
of nomenclature is so free from material imperfections as to bo
referred to as a standard of authority, it becomes necessary for
every one who treats on soils to define for himself ; though perhaps
he may thereby add still more to the general mass of confusion
previously existing. This necessity must serve to excuse the writer
for whatever is new, unauthorized, or confessedly defective in the
definitions and terms which will be here adopted, and used as
required hereafter through this treatise. It would be inferred by
most readers, from the general heading alone, that this introductory
chapter must consist mainly of definitions and explanations already
established by scientific authority, and generally received by and
known to well-informed agriculturists. This inference would be
correct to a considerable extent : nevertheless, there will be many
2* (17)

18 DIFFICULTY OF DEFINING EARTHS AND SOILS.

of the views wliich are either new and unsupported, or entirely
opposed to all existing authority ; and which will require to be
understood and borne in mind by all who desire to study with pro-
per advantage the theory of fertilization which will be presented
and maintained in this essay.

Previous to the recent attention of chemists directed to agricul-
ture, which may be said to have begun with the publication of
Pavy's admirable and very valuable (though necessarily very im-
perfect) work on the ^' Elements of Agricultural Chemistry,"
agricultural writers had defined and described soils by their quali-
ties obvious to the senses, and without much, if any, regard to
their chemical, or even their physical constitution. Of course
they were often in error; as the sensible qualities, or textures of
soils, do not always quadrate with, or conform to the proportions
or kinds of their materials. For example : an open and light soil,
is most generally made so by an excess of silicious sand ; but occa-
sionally soils owe their possessing this texture to an excess of
humus or vegetable matter, or of chalk ; and which soils may be
greatly deficient in sand, and would be rendered even more com-
pact by an addition of this earth. Again : the closeness and in-
tractability of a soil is generally owing to the excess of clay ; but
a soil superabounding in clay, with large intermixture of vegetable
and calcareous earths, may be much more friable and light than
another with much less clay, and much more of silicious sand in a
very finely divided state.

More recently, when many men of science took their present
ground as co-labourers in agricultural investigation, they brought
to bear, on this branch of the science, terms and definitions exact
and precise enough indeed, they being those recognised in chemis-
try; but altogether inapplicable to agriculture, because referring
to conditions of purity, and simplicity of composition, having no
existence in nature, nor even subject to the observation and senses
of the agriculturist. Hence, when chemists, using their scientific
nomenclature, attempt to instruct farmers of the composition of
soils, and refer to their contents of the chemical earths proper,
alumina, lime, magnesia, &c., they are speaking of things which
have no existence in nature, nor even in agricultural art ; and they
might as well go farther back in search of scientific strictness, and
treat of the elementary parts of these several earths — that is, oxy-
gen, with the metals aluminum, calcium, and magnesium, respect-
ively ; which elements are rarely produced or preserved separate,
and never except in the chemist's laboratory. The substances
known in chemistry as earths, are, indeed, defined with precision,
and their distinguishing properties are well understood by those
who are even slightly acquainted with that science. But of the
nine earths known to chemists, one only, silica^ exists naturally in

AGRICULTURAL EARTHS. 19

a state of purity, or uncompounded ; and in this state of purity (as
rock-crystal, or pure quartz-rock), it can have no action whatever
as an agricultural earth. Two other chemical earths, alumina and
lime, are only found combined with other bodies; and, as thus
combined, exhibiting very different properties from the pure earths,
which can be produced only by chemical decomposition. A fourth
earth, magnesia, likewise is never found uncombined, and rarely
in other than very minute proportions, and always intermixed
with other earths, so as to be imperceptible by the senses. The
other chemical earths (barytes, strontian, zircon, &c.) are so rarely
found, and still more rarely in soil, and most of them only in such
minute quantities that, as to any influence on agriculture, they may
be deemed as non-existent.*

These few preliminary remarks will serve to expose something
of the dif&culty of distinguishing and clearly defining the earths of
agriculture. That the attempt which will here be made will but
imperfectly reach the desired object, will not be more evident to
other persons than to the writer.

The agricultural earths will here be understood as bodies natu-
rally existing, and, when separate, as pure as ever presented by
nature ; and of which, each one, except humus, is composed princi-
pally of some one chemical earth. They are five in number — silicious,
aluminous, calcareous, magnesian, and vegetable or humus. Those
agricultural earths, variously intermixed, serve to compose the
superficial layer of the globe. This layer, more or less productive
of vegetable growth, is &oil ; and however varying in difi*crent
places, all soils, for almost their entire bulk, are composed of one
or more of the three principal agricultural earths — the silicious,
aluminous, and calcareous, with more or less of humus, or vegetable
mould. It is convenient, though still a farther departure from
scientific strictness of definition, to include humus among the earths
of agriculture.

1. Silicious earth is presented in the cleanest, most crystalline,

■^ The chemical earths are combinations of different metals (which are
known only in these combinations) mth oxygen. Before Davy's splendid
discovery of these metals, and their combinations with oxygen, the earths
were supposed to be simple bodies, or incapable of being decomposed. A
single combination of one of these very rare chemical eartlis, the sulphate
of barytes, has been recently found to be a very effective manure, acting
on clover with the remarkable power of sulphate of lime (gypsum). Pro-
fessor Armstrong, of Washington College, has fully tested it by the practi-
cal use of the earth as manure. lie also informed me that tlie sulphate
of barytes was found in some parts of that mountain region in sufficient
quantity to be used for manuring, in the small proportions required for its
effects. These interesting facts do not contradict the remarks in the text
above, which referred to barytes and the other scarcer earths only as cou-
etituents of soils.

20 SILICIOUS AND ALUMINOUS EARTHS.

whitest, and purest sand, as washed and deposited by rapid streams,
or other water in motion. This, the very abundant agricultural
or natural earth, often approaches nearly in purity to the chemical
earth silica. Silicious earth generally appears as sand ; that is,
in separate and loose grains of small size, which are rugged and
irregular in shape, usually with sharp angles, rough to the touch,
and hard enough to scratch glass. This earth is not soluble in any
acid except the fluoric, and cannot be made coherent by any mix-
ture witli water. The solidity of the particles of sand renders each
one impenetrable by water ; and their loose and open arrangement
permits water to pass easily through the mass. The same condi-
tions of impenetrable grains and loose and open texture cause silicious
earth to be incapable of absorbing moisture from the air, or of re-
taining, with any force, either moisture or any aerial or gaseous
fluid with which it may have been in any manner supplied. Sili-
cious earth is also quickly and strongly heated by the sun, which
increases the rapidity with which it loses moisture.

2. Aluminous earth, or argily or purest clay, as it may also be
called for convenience, is composed, for a large part, of the chemical
earth aluminaj from which this and all other less pure clays derive
their peculiar and well-known qualities. Still, this purest of clays,
naturally existing (or " pipe clay," as termed by some agricultural
chemists), contains no more than 36 to 40 per cent, of alumina,
chemically combined with 52 to 60 per cent, of silica, and 3 or 4
per cent, of oxide of iron.* Thus even the purest natural clay, or
aluminous earth, does not approach the purity of the chemical earth
alumina within some 60 to 64 per cent. And all ordinary and less
pure clays, of course, have much more of silicious sand, the additional
quantity being in the state of mechanical mixture. Aluminous
earth and all clays, in proportion to their purity, when dry, absorb
water abundantly; and when wet, form tough and ductile paste,
smooth and soapy to the touch. By burning, the mass becomes
brick, hard like stone, and is no longer capable of being softened
by water. When drying from a previous wet and softened condi-
tion, aluminous earth and all clays shrink greatly, and, separating
by numerous cracks and fissures, the mass is broken into hard
lumps.

3. Calcareous eartli, carbonate of lime,'f or calx, is the next

* Prof. J. F. W. Johnston's "Lectures on the Applications of Chemistry
and Geology to Agriculture," p. 230, ei seq. First Am. edition of Wiley
and Putnam, New York, 1844.

•j- Carbonate of lime is the chemical name for the substance formed by
the combination of carbonic acid with liine. The names of all the thousands
of different substances {neutral salts) which are formed by the combination
of each of tlie many acids with each of the various eartlis, alkalies, and
metals, are formed by one uuiform rule, which is as simple and easy to be

CALCAREOUS EARTH. 21

most abundant agricultural earth. It is a combination of tlie clie-
mical earth lime with carbonic acid, in the constant proportions
(in whole numbers) of 56 parts lime to 44 of carbonic acid. It is
converted to pure or quick-lime by red heat, which drives off the
carbonic acid; and quick-lime, by exposure, and attracting carbonic
acid from the atmosphere, soon reverts to its original condition of
carbonate, or calcareous earth. It forms marble, limestone, chalk,
and shells, with very small admixtures of other materials. Thus
the term calcareous earth will not be used here to include cither
lime in its pure state, or any of the numerous combinations which
lime forms with the various acids, except the one combination
(carbonate of lime) which is beyond comparison the most abundant
throughout the world, and most important as an ingredient of soils.
Pure lime attracts all acids so powerfully, that it is never presented
by nature except in combination with some one of them, and generally
with the carbonic acid. When this compound is thrown into any
stronger acid, as the muriatic, nitric, or even common vinegar, the
lime, being more powerfully attracted, unites with and is dissolved
by the stronger acid, and lets go the carbonic, which escapes with
effervescence in tlie form of air. In this manner, the carbonate of
lime, or /calcareous earth, may not only be easily distinguished
from silicious and aluminous earth, but also from all other com-
binations of lime.

The foregoing definition of calcareous earth, which confines that
term to the carbonate of lime, is certainly liable to objections, but
less so than any other designation. It may at first seem improper
and even absurd to consider as one of the principal earths which
compose soils, one only of the many combinations of lime, rather
than either pure lime alone, or Time in all its comhinations. One
or the other of these significations is adopted by the highest autho-
rities, when the calcareous ingredients of soils are described ; and
in either sense, the use of this term is more conformable with
scientific arrangement than mine. Yet much inconvenience is
caused by thus applying the term calcareous earth. If applied to

understood and remembered as it is useful. To avoid repeated explana-
tions in the course of this essay, the rule will now be stated by which these
compounds are named. The termination of the name of the acid is changed
to the syllable ate, and then prefixed to the particular earth, alkali, or
metal with which the acid is united. With this explanation, any reader
can at once understand what is meant by each of some thousands of terms,
none of which might have been heard of before, and which (without this
manner of being named) would be too numerous to be fixed in the most
retentive memory. Thus, it will be readily understood that the carbonate
of magnesia if a compound of the carbonic acid and magnesia — the sulphate
of lime a compound of sulphuric acid and lime — the sulphate of iron a com-
pound of sulphuric acid and iron — and in like manner for all other terms
so formed.

22 CALCAREOUS EARTH.

lime, it is to a substance which is never found existing naturally,
and which will always be considered by most persons as the artifi-
cial i3roduct of the process of calcination, and as having no more
part in the composition of natural soils than the manures obtained
from oil-cake or pounded bones. It is equally improper to include
under the same general term all the combinations of lime with the
fifty or sixty various acids. Two of these compounds, the sulphate
and the phosphate of lime, are known as valuable manures ; but
they exist naturally in soils in such minute quantities, as not to
deserve to be considered as important physical ingredients. Many
other salts of lime are known to chemists; but their several quali-
ties, as affecting soils, are entirely unknovrn — and their quantities
are too small, and their presence too rare, to require consideration.
If all the numerous different combinations of lime, having perhaps
as many various and unknown properties, had not been excluded
by my definition of calcareous earth, continual exceptions would
have been necessary to avoid stating what was not meant. The
carhonate of lime, to which I have confined that term, though only
one of many existing combinations, yet in quantity and in import-
ance, as an ingredient of soils, as well as a part di the known por-
tion of the globe, very far surpasses all the others.

But even if calcareous earth, as thus defined and limited, is ad-
mitted to be the substance which it is proper to consider as one of
the important earths of agriculture, still there are objections to its
name which I would gladly avoid. However strictly defined, many
readers will attach to terms such meanings as they had previously
understood : and the word calcareous has been so loosely and so
difi"erently applied in common language, and in agriculture, that
much confusion may attend its use. Anything " partaking of the
nature of lime'' is " calcareous,' ' accordingto Walker's Dictionary;
Lord Kames limits the term to pure lime ;* Davyf and Sinclair^
include under it pure lime and all its combinations; and Kirwan,l|
Kozier,*! and Young,§ whose example I have followed, confine the
name calcareous earth to the carbonate of lime. Nor can any other
term be substituted without producing other difficulties. Carhon-
ate of lime would be precise; but there are insuperable objections
to the frequent use of chemical names in a work addressed to ordi-
nary readers, and this one would be especially awkward and incon-
venient for such use. Chalk,'or shells, or mild lime (or what had
been quick-lime, but which, from exposure to the air, had again

* Gentleman Farmer, page 264 (2d Edin. ed.)

t Agr. Cliem., page 223 (Phil. ed. of 1821.)

X Code of Agriculture, page 134 (Hartford cd. 1818.)

jl Kirwan on Manures, chap. 1.'

\ " Terres" — Cours Complet d' Agriculture Pratique.

§ Young's Essay on Manures, chap. 3.

CALCAREOUS EARTH. 23

become carbonated), all these are the same chemical substance ; but
none of these names would serve, because each would be supposed to
refer to such certain form or appearance of calcareous earth as they
usually express. If I could hope to revive an obsolete term, and,
v/ith some modification, establish its use for this purpose, I would
call this earth c«/x— and from it derive calxmg, to signify the
application of calcareous earth, in any form, as manure. A general
and definite term for this operation is much wanting. Liming,
marling, applying dravm ashes, or the rubbish of old buildings,
chalk, or limestone gravel, all these operations are in part, and
some of them entirely, that manuring which I would thus call
calxing. But because their names are different, so are their efiects
generally considered — not only in those respects where differences
really exist, but in those where they are precisely alike.

Calcareous earth, in the agricultural sense here assumed (calx,
or carbonate of lime), has almost no existence as an ingredient of
soil throughout all the great Atlantic slope of the United States
north of Florida. Nor has it any existence, separate from soil,
unless as lime-stone rock and travertine in the mountain region,
and subterranean beds of fossil shells in the tide-water lands. In
England, France, and some other parts of Europe, this earth occurs
as chalk, in beds of great thickness and vast extent of surface. The
whiteness of chalk repels the rays of the sun, and its open texture
permits -^vater to sink through almost as easily as through sand.
Thus calcareous earth alone, or when constituting the bulk of a
soil, is remarkable for possessing some of the worst qualities of
both sand and clay.

But though the true chalk, which is so widely spread in Europe,
does not exist in North America, there are very extensive regions
of this continent of which the soils are composed in part, and their
subsoils mainly, of calcareous earth, and which may be considered
as chalk soils and subsoils in an agricultural, though not a geo-
logical sense. Such are most of the '^ prairie" lands of Alabama,
Mississippi, and Arkansas ; and (as I infer from analogy) of Texas,
and of the vast prairie region west of the Mississippi Biver. The
"everglades'' of Florida, as I infer, and the nearest sea islands
also, are of like constitution. The subsoil and inferior layers,
known in many cases to be several hundred feet tWck, are like an
impure chalk, composed principally of carbonate of lime (of which
there is a proportion from 70 to more than 80 per cent.), inter-
mixed intimately, or combined, with fine clay, which constitutes the
small remaining part. This great formation of impure calcareous
earth may be considered as either a very rich marl, or a poor chalk ;
and similar to true chalk in every relation to agriculture, except (in
consequence of its argillaceous admixture) in being, in most cases,
as much impervious to water as true chalk is the reverse.

24 MAGNESIAN EARTH.

4. It seems doubtful whether magnesia, in any form or condition,
should be counte(^ among the earths of agriculture, or physical
constituents of soils. Though very generally diffused through soils,
it is usually in extremely small proportions. In this country, so
far as my personal observation or other information has extended,
no soil is known to contain magnesia, in any form, as a physical
or considerable constituent ; and even as a chemical or manuring
agent, the quantities present in soil have been so small, and, more-
over, so associated with larger proportions of the kindred earth
lime, that the effects of the magnesia alone could not be appre-
ciated. Nor are the chemical effects of magnesia much better
known in Europe, where they are more obvious to observation, and
have been more or less remarked upon by all agricultural chemists.
They have been considered by most writers as injurious to the fer-
tility and productiveness of soils. But, though without any
evidence of facts, I would infer the reverse operation of magnesia
in small proportions. The grounds of this inference are presented
in the general similarity of chemical character of magnesia to lime
— and also the very general diffusion of magnesia, in some form of
combination (though not often as carbonate), in soils, and espe-
cially the richest soils.*

In other parts of the world, however, magnesia is much more
abundant. It is present in large and (as there supposed) injurious
quantity in the Gatinais (between the rivers Seine and Yonne), in
France,f and also in Cornwall, in England. J

Magnesia very much resembles lime in most of their known
qualities, and especially in their respective chemical af&nities to
other bodies. The resemblance is perfect in this important respect,
that tlie pure chemical earth magnesia has no natural existence,
because of its strong attraction for acids. If made pure by art, it
is then the ^' calcined magnesia' ' of druggists. In that artificial
state, and in which only the pure chemical earth ever exists at all,
if exposed to the atmosphere, it soon attracts carbonic acid, and so

* In a specimen of the celebrated rich alluvial soil of Red River,
Louisiana, I found from 1 to 2 per cent, of carbonate of magnesia ; and
something less in the equally rich deposit of the Mississippi River, on the
Arkansas shore. The rich mud of the Nile contains 4 per cent, of this
earth. (Regnault, quoted by Boussingault), Rural Economy, &c., p. 338,
(1st Am. ed., 1845.)

f These peculiar soils were described at length in the ^^ Annates d' Agri-
culture Frangaise," by M. Puvis, whose article was translated for and pub-
lished in the Farmer's Register, vol. iv., p. 212, accompanied by my reasons
for doubting the conclusions of the author as to the magnesia being the
cause of sterility.

X The Lizard Downs. (Davy.) This soil is formed in part by the disen-
tegration of the underlying serpentine, a magnesian rock. (J. F. >V.
Johnston.)

HUMUS, OR VEGETABLE EARTH. 25

becomes the carbonate of magnesia, which is the ordinary mild
substance used as medicine. This is a combination of 48 parts of
magnesia with. 52 of carbonic acid. It is to this compound only,
the carbonate of magnesia, I affix the term of magnesian earthy
and not to any other form of combination with other earths or with
acids, nor to the pure chemical earth magnesia, whic^ has no exist-
ence in nature, and, of course, can have no natural influence on
soils or on agriculture.

5. Humus is the partially decomposed remains of dead vegetable
growth, reduced by time to nearly an earthy texture, pulverulent
when dry, and soft and slimy, and almost semi-fluid when full of
water. This vegetable earth, as peat, and in its purest state, is
very abundant in Great Britain and other cool and moist countries.
But in Eastern Virginia, it has scarcely any existence, separate or
alone, except in the Great Dismal Swamp, and in marshes covered
by the tides. In these places, and also in the still larger swamps
of North Carolina, the continual wetness and dense shade serve to
prevent the complete decomposition of vegetable matter, as is done
in Europe by the prevalence of cloudy and damp air, find low
average temperature; and under such condhionsonly, in cnr hotter
and dryer climates, does humus occur alc-ne, or even t^s forming
the principal material of any soiJ. The peat soil of E'.ir ps is com^^
posed of pure vegetable matte ?, for 60 per cent, or morr^ of its dry
weight. (Johnston.) The peat r.sed for fuel is probably still more
of vegetable constitution. Of four spechnens of soil of the Dismal
Swamp, selected and examined by myself, the vegetable parts were,
respectively, 75, 90, and, in the other two, 96 per cent, of the
hulk of the soil. Difierent specimens of soils, from both salt and
fresh-water tide marshes, bordering on Powhatan (or James)
River, lost full 50 per cent, of their dry weight by being burnt
thoroughly ) showing that half their weight, and probably five-sixths
of their bulk, is pure vegetable matter. These soils are, per-
haps, as near to pure humus as any in our climate.

As a small, or chemical ingredient of soil, intermixed or com-
bined with other earths and far more abundant mateiials, humus
is present universally, serving as aliment to be drawn up by the
roots of growing plants, and without which no healthy or luxuriant
growth could be produced. Humus gives colour and value to the
black rich mould of old garden ground, and to the richest forest or
alluvial soils, before they are reduced in fertility by tillage.

Soils and Sub-soils in General.

All the agricultural earths, including humus as one, when sepa-
rated pure, or as nearly pure as ever presented by nature, are
nearly or entirely barren. This might be inferred from the mere
3

26 SOILS AND THEIR COMPOSITION.

description of their respective qualities. Further — the too large
proportion of any one earthy in the mixture of several, is injurious
to fertility in proportion to such excess. But the quantity which
would thus be hurtful by excess would be very different in the dif-
ferent earths, and also as to each one, as modified by attendant
circumstances! Thus, as a supposition, or, at best, a mere ap-
proximation to truth, we may suppose the following named pro-
portions to be as large as can be present, respectively, in different
soils, and under ordinary circumstances, without being injurious
to production : —

Silicious earth (as pure sand), in a particular soil,
will be injurious by its excess, if more in propor-
tion to the soil than - - - - 85 per cent.

Or aluminous earth (argil, or purest clay), in ano-
ther soil, - - - - - 25 <<

Or calcareous earth (carbonate of lime, or calx), in

another, - - - - -5?"

Or magnesian earth (carbonate of magnesia), in

another, - - - - - 2? "

Or humus (nearly pure vegetable matter), in another, 12 ? "

In such large proportion as indicated by the above quantities,
the greater part of each earth could act only physically or mecJian-
ically. If considered merely as chemical or manuring constituents,
and embraced in one soil, perhaps one per cent, of calx, a mere
trace of magnesian earth, and five per cent, of humus, would be
enough ; while nearly all the remainder of the hundred parts would
be of silicious earth mainly, and aluminous earth, serving merely as
physical constituents, for nearly their whole quantities.

But whatever may be the most suitable proportions, and however
much the action and power of each one may be in some cases
modified by other ingredients, or by attendant circumstances, still
the admixture, in due proportions, of the different earths will serve
to correct the defects of all, and thus to form soils of every charac-
ter and variety. And various as are the soils naturally formed by
mixtures of some or all of the different earths, and greatly defective
as most of them are, there are but few which do not more or less
fulfil their purpose of serving to sustain the growth of useful plants ;
in which they may extend their roots freely, yet be firmly sustained
in their erect position ; and obtain the necessary supplies of air,
moisture, warmth, and food, without being too much oppressed. by
the excess of either. Such are the soils, though of various pro-
portions and values, on all the surface of the globe wherever fit
for culture. And though the qualities and values of soils are as
various as the proportions of their ingredients are innumerable,
yet they are mostly so constituted that no one earthy ingredient is

SOILS AND SUB-SOILS. 27

SO abundant but that tbe texture* of the soil is mechanically suited
to some one valuable crop; as some plants require a degree of
closeness, and others of openness in the soil, which would cause
other plants to decline or perish.

The depth of soil seldom extends more than a few inches below
the surface, as on the surface only are received those natural sup-
plies of vegetable and animal matters, which are necessary to con-
stitute soil. Valleys subject to inundation have washings of soils
brought from higher lands and deposited by the water, and there-
fore are of much greater depth.

Below the soil is the sub-soil, of uncertain depth, and which need
not be considered as extending deeper than its texture or condition
may affect the production of the soil above, whether beneficially or
injuriously. It is, however, most common that the sub-soil is ap-
parently nearly of the same constitution with the subjacent mass for
several or many feet deeper. The sub-soil is usually a mixture of
two or more earths, and the same as may predominate in the soil
above. But the sub-soil is much more deficient in calcareous earth
(except under chalky soils), and lime in every state, and also in
humus; and, indeed, nearly all sub-soils in lower Virginia are
totally deficient in all those ingredients essential to vegetat)le pro-
duction. Even where such absolute deficiency may not exist, the
usual great excess of either sand or clay in sub-soils would alone
serve to render them nearly barren ; and, consequently, their mix-
ture with the better soil lying above would be injurious rather than
beneficial to its improvement.

The qualities and value of soils depend on the proportions of
their ingredients. We can easily comprehend in what manner
silicious and aluminous earths, by their mixture, serve to cure the
defects of each other ; the open, loose, thirsty, and hot nature of
sand being corrected by, and correcting in turn, the close, adhesive,
and water-holding qualities of aluminous earth. This curative
operation is merely mechanical ; and in that manner it seems likely
that calcareous earth, when in large proportioiis, and serving as a
mechanical constituent, also acts, and aids the corrective powers of
both the other earths. This, however, is only supposition, as I
have met with scarcely any such natural soil.

But besides the mechanical effects of calcareous earth (which
are weaker than those of the other two), that earth has chemical
powers far more effectual in altering the texture of soils, and for
which a comparatively small quantity is amply sufficient. The
chemical action of calcareous earth, as an ingredient of soils, will
be fully treated of hereafter j it is only mentioned in this place to

* The texture of a soil means the disposition of its parts, which produces
Buch sensible quahties as being close, adhesive, open, friable, &c.

28 PHYSICAL AND CHEMICAL CONSTITUENTS OF SOILS.

avoid the apparent contradiction which might be inferred, if, in a
general description of calcareous earth, I had omitted all allusion
to qualities that will afterwards be brought forward as all-important.

Physical (or MeclianicaT) and Cliemical Constituents of Soils.

In the discussion of this general subject, we should always bear
in mind the different actions of the earths as the jjhi/sical, or me-
chanical, and the chemical ingredients of soils. These different
actions have already been incidentally referred to ; but they require
more particular notice.

Any of the earths which may serve as large materials in the
composition of a soil, must act, for much their greater proportion,
merely mechanically in the relation of the soil to the grow'th of
plants. Thus, the various mixtures of silicious and aluminous
earths existing in all ordinary soils — and these more rarely with
large proportions of either calcareous or magnesian earth, or humus
— serve, for much the larger proportions of each and all, to furnish
merely that mechanical position and support for growing plants
which is necessary for them to draw freely the available supplies
of water, air, and food. The conditions necessary for this purpose
are, that the soil shall have enough sand to be sufficiently permeable
by moisture, and for the extension of the rootlets ; that there shall
be enough clay to give firm support to the plant in its upright
position, and sufficiently to close the too great openness of thfi'sand.
These necessary physical conditions of the soil, in relation to its
texture and powers of receiving, retaining, and transmitting moist-
ure, are further improved, and opposite evils either modified or
prevented, by additional admixtures of calcareous (and perhaps
magnesian) earth, and humus. But so far the action of each and
all these materials, in large quantities, (and for much the larger
proportion being always understood), act only by their physical
qualities, and exert such powers in proportion to quantities. Any
one of these materi^Js, for much its greater part, might be substi-
tuted by some other, if offering like physical qualities, though
totally different in chemical character and constitution. Thus,
when chalk greatly predominates in soil disposed to dampness,
from position or climate, its physical qualities serve to increase the
evil, as would clay ; and the soil is both colder and wetter than if
there were no physical action of the calcareous earth. On the
other hand, in a soil disposed to suffer by dryness, the like chalky
constitution would increase that evil, as would sand, by its open
texture permitting the too rapid escape of moisture. Humus, in
large proportion, acting mechanically lik:e clay, serves to close the
too open pores of sandy soils ; and, by its remarkable absorbent
power; to make them more retentive of moisture wherever excess

PHYSICAL AND CHEMICAL CONSTITUENTS OF SOILS. 29

of moisture exists. Yet in a soil largely composed of clay, and as
much deficient in sand, a very large natural supply of humus will
prevent the tenacity and intractability which the clay otherwise
would have induced ; and cause the soil, when dry, to be friable,
loose, and permeable. In wet seasons, however, the same soil will
be again too close and adhesive.

Further — if we can conceive that other materials could be sub-
stituted, having entirely different chemical characters, they might
serve as well for physical constituents of soils, as the earths of
which they took the place. Thus the purest clay, or even pure
alumina, if calcined to the state of brick, and then reduced to fine
grains, would serve the same physical purposes in soil as silicious
sand. And if an artificial soil were thus composed, it might have
all the physical qualities of the most sandy soil, while its chemical
composition would be more aluminous than ever exists in nature.

The physical or mechanical action of earths has been kept gene-
rally in view through the foregoing pages, inasmuch as the earths
have been considered as forming large ingredients of soils. But
besides this more obvious action of the agricultural earths, all of
them, as well as many other different bodies, act also by chemical
power. For the fullest exercise of this power by each, compara-
tively very small proportions of each ingredient are required. In
a soil composed of any proportion whatever of silicious, aluminous,
calcareous, magnesian, and vegetable earths, perhaps the quantity
of each acting chemically, might not exceed the hundredth, if the
thousandth, part of the whole mass of soil — all the remainders of
each earth, whether great or small, having, for the time, no other
than mechanical action.

But the magnitude and importance, and value to the farmer, of
the mechanical and chemical ingredients of soils are not at all in
proportion to the quantities required to exert the different powers.
The chemical action is much the more valuable in effect and benefit
produced ; and also because the producing agents, from the small
quantities required, are more or less under the control of man ;
while the great quantity alone of any material required for physical
effect, would generally place it entirely beyond control.

All cliemfiical ingredients of soils, whether of the agricultural
earths which also make the universal mechanical materials, or of
any other bodies so far as they operate in soils by chemical action,
are inanures, which serve directly or indirectly, immediately or
remotely, to give food to and promote the growth and production
of plants.

ThuSj'-according to my views, and in the sense in which I use

the terms, the jyJii/sical or mechanical constituents of soils, and the

agricultural earths, when serving as earths, are the same; and

also, that so much of these earths as act chemically, or as chemical

3*

30 PHYSICAL AND CHEMICAL CONSTITUENTS OF SOILS.

constituents of soils, are manures. The same substance (whether
silicious sand, clay, chalk, or humus) which, when in quantity, and
for the much larger proportion of such quantity, is a mere earth,
or mere physical material, also, for a very small proportion, in the
same or other soil, acts chemically and as a manure. And these
different operations of the same substance may even oppose each
other ; and then it will depend on other circumstances whether the
manuring action of a minute proportion of the substance will do
more good than is produced of injury by the excess of the same
substance as an agricultural earth and physical material of the
soil.

If I have succeeded in clearly showing the distinction of me-
chanical and chemical action in soils of even the same substances,
it will serve to remove much of the obscurity and mystery which
have attended the general subject. When the application of cal-
careous matter as manure is new, or but beginning in any country
(as in Virginia thirty years ago), it has been deemed (by many par-
tially informed persons) a sufficient objection to the promised
benefit of a small application, that much larger natural proportions
elsewhere did not always make rich lands. It seemed incredible
that a proportion of calcareous earth less than 1 per cent, of the
soil could much promote its fertilization and productiveness, when
other soils had 5, 10, or 50 per cent, of that material, and were
not always rich, and in some cases were extremely barren. But,
in such cases, 1 per cent, (or less), perhaps, was as large a pro-
portion of carbonate of lime as could act chemically and as a ma-
nure. All beyond that proportion would be mere physical material ;
and if in excess even for it^ mechanical operation, would be injuri-
ous in proportion to its excess. Thus (as will be shown hereafter)
a very small proportion of this earth serves to lessen the evil effects
to soils of both too much wetness and too much dryness, and the
opposite evils of too much heat and also of low temperature. But
in a chalky soil, where this ingredient is in great quantity, the
mechanical action predominates and overpowers the chemical ; and
such constitution of soil serves to aggravate all the opposite evils
of dryness and moisture, heat and cold, which the chemical action,
if alone, would greatly mitigate.

The perplexity and erroneous deductions which have prevailed
have been much increased by some writers of scientific celebrity.
From analyzing specimens of remarkably fertile soils, and finding
in most cases very large proportions of carbonate of lime, they have
absurdly inferred that these were the most proper proportions.
Hence, different chemists have indicated as the most suitable for
the highest fertility of soil, proportions of this earth varying from
2 to 30 per cent, of the whole mass of soil. They who advocated
the larger quantities were ignorant that perhaps nine-tenths of the

CLASSIFICATION OF SOILS. 81

lime was either inert earth, or positively hurtful by its peculiar
mechanical action ; and that such soils, when highly fertile (as the
mud of the Nile, with its 25 per cent.), were so by aid of their
other useful ingredients, which enabled the soil to withstand the
evil operation of the greater portion of its lime.

It is scarcely necessary to state that neither of the agricultural
earths applied to soil can serve as a manure (i. e., have any chemi-
cal action), when there is already enough of the same earth present
to have any mechanical action. And however useful each of the
earths may be if applied where its chemical action is deficient, it
would be as absurd in reasoning as useless in practice, to apply
sand to sandy, and clay to clayey soils, or lime to the chalky, or
vegetable matters to peaty soils.

The foregoing definitions and explanations offer some materials,
or ground-work, for the classification of soils. But, greatly as that
is needed, it is not designed here to attempt the construction of a
proper general classification or nomenclature — which would serve to
add another failure to those of all preceding writers on soils. But
as it is impossible to discuss the subjects to be presented for con-
sideration in this essay without the use and aid of some definite
terms, I will adopt, for present and provisional use, the following
general terms for soils, deduced from their respective predominant
or most operative physical ingredients, and which will have rela-
tion only to mechanical constitution, and such qualities and cha-
racters of soils as are generally indicated by their texture, and are
evident to the senses.

In reference, then, to physical predominating ingredients only,
each of the agricultural earths above described, by its quantity,
serves to make a different general character of soil — which, accord-
ing to the predominant physical constituent earth, belongs to some
one of the following five classes or general divisions of soils : —

1. A silhcious or sandy soil contains so large a proportion of
silicious earth, in the state of sand, as by its excess to give more
or less of the peculiar texture and mechanical qualities of that earth
to the soil. Thus, a silicious or sandy soil will show most strongly
such qualities as openness, looseness, want of adhesiveness when
wet, permeability, rapidity in drying, &c., such as are still more
strongly shown by pure silicious sand.

2. An aluminous, argillaceous, or clayey soil contains such ex-
cess of aluminous earth, or purest clay, as will give to the soil the
qualities of adhesiveness and plasticity when wet, more or less of
obstruction to the passage or sinking of rain-water, great tendency
to shrink in drying, and to hardness when dry, &c.

3. A chalky, or super-calcareous soil, whether made so by true
chalk, or by any other form of calx or carbonate of lime, from any
other source, contains an excess of that agricultural earth large

<J2 CLASSIFICATION OP SOILS.

enougli to be injurious, in any of the modes indicated to the phy-
sical properties above stated of that earth. No such soil exists in
all Virginia, nor in any other of the Atlantic States north of
Florida.

As these general divisions of soils are determined according to
their predominating or most operative physical ingredient only,
the term calcareous soil (of which such frequent use will be made
in this essay) has been designedly omitted above. But to prevent
misapprehension, it will be merely mentioned, in anticipation, that
calcareous soil will be hereafter used as a still more comprehensive
term, embracing not only all the super-calcareous soils, but all
others that contain even the smallest appreciable proportion of car-
bonate of lime. Generally, however, the term calcareous will be
that applied to soils in reference to their contents of small and
harmless proportions of carbonate of lime (acting as a chemical
constituent only or mainly) ; while those having larger and hurtful
proportions will always be contra-distinguished as the chalky or
super-calcareous. *

4. A magnesian soil would be one in which magnesian earth
is in sufficient excess to make its physical qualities predominate
over the other earths serving as ingi-edients. Such soils are of
doubtful existence ; certainly of extremely rare occurrence.

6. A humic, x^eati/j or vegetable soil, has so large a proportion
of humus that it is either injurious to production, or otherwise
serves to counteract and overbalance the opposite injurious qualities
of some other ingredient. Thus, a soil which by its aluminous
constitution alone would have been very clayey, or another which
would otherwise have been chalky, might have either of such de-
fects of texture, &c., counteracted, and partially remedied, by a
greater predominance of humus ; and thereby be made a humic
instead of either a clayey or chalky soil.

For an earth to be 'predominant and excessive in a soil, as un-
derstood above, and so to convey its qualities and its name, it is
not necessary that it shall be the ingredient grea;test in quantity —

* The previous difficulties of de£r.icion and of underatancLJig on this
head, woul l be greatly increased bj adjiitihig the strange n c'^ 3.1 viator e of
the latest \vriter, Profess -■;r J. F. W, JohnEton, whose authcrltv stands so
high, and is so generally Tro-'thy of respect. He confines the term *• cal-
careous soil"" (by express defin tion) t? such as contain mere tJian 20 per
cent, of carbonate of lime ! Those containing from 5 to 10 per cent, ho
terms "marly soils;" and all containing less than 5 per cent, are left
without any distinguishing term or character in regard to their calcareous
constitution. (Johnston's Lectures, p. 233.) According to these designa-
tions, there would not be an acre of natural "calcareous soil," or even
of "marly soil," in all Virginia; nor will there be, after all that shall be
judiciously done by the industry of man in supplying calcareous manure
to the soils deficient in that ingredient.

DEPiNnio-N's OP SOILS. 33

wliich only is always the case as to silicious earth. Of this, in its
pure and iincombined state, as sand (capable of being separated by
washing in water), it requires a very large proportion, say not less
than 80 per cent, of the whole mass, to constitute a sandy soil.
But, in other soils, though consisting for much more than half their
mass of uncombined silicious sand, a much smaller proportion of
either one of the other earths would serve to make the latter the
predominant ingredient, and properly to give character and name
to the soil. Thus, from 35 to 40 per cent, of " purest clay" (which
itself contains about 60 per cent* of silica), or 30 per cent, of calx,
or 25 per cent, of humus, or perhaps less of each, under ordinary
conditions, would serve to constitute, respectively, either a clayey,
a chalky, or a humic soil ; though, in each case, the other and
much larger ingredients would be other earthy materials than the
one so predominating.

But even in soils having some one physical ingredient sufficiently
predominant and distinguished to indicate their general character and
name, there also^re usually apparent the manifest though weaker
indications of the presence of some other influential ingredient.
For such compound qualities, terms may be cor -pounded of the
foregoing, which will sufficiently express the characters referred to.
For this purpose, there will be found a convenience in using also
the term loam for all soils approaching to a medium texture and
composition of the two usually most abundant ingredients, silicious
sand and clay — or soils in which the opposite qualities of silicious
and aluminous earths serve in great measure to correct each other,
leaving no great or injurious excess of either. Such a medium
texture, or soil approaching nearly to such, would be simply a loam.
If still more sandy, it might be termed a sandy loam, ; or a clayey or
chalky, or peaty loam, under other conditions of physical constitu-
tion. Besides all these and other such compounded terms, others
may be used for other physical and accidental qualities of soils, as
stony, gravelly, ferruginous, &c., any of which may apply to any
soil of different predominant character, and different general de-
signation.*

* The convenient and very common term loam is defined above (it is pre-
sumed) with enough precision and correctness ; and also in accordaiice with
common understanding. Yet this term offers (next, perhaps, to "marl")
one of the strongest examples of the conflict of definitions and confusion
which prevail among agricultural writers. This term is so common that it
is used by every one who writes of soils — aivl wldch, in some one or other
sense, each writer probably considered as torming a very large, if not the
greatest proportion of the cultivated soils of his country, and of the world.
Some of various and contradictory and erroneous definitions will be here
quoted : —

ICirwan says — " Loam denotes any soil moderately cohesive, and more so

CHAPTER II *

ON THE SOILS AND STATE OP AGRICULTTJRE OP THE TIDE-
WATER DISTRICT OP VIRGINIA.

-'^During several days of our journey, no spot was seen that

was not covered with a luxuriant growth of large and beautiful
forest trees, except where they had been destroyed by the natives
for the purpose of cultivation. The least fertile of their fields,
when left untilled and without seeding, are soon covered with grass
several feet in height j and unless prevented by subsequent culti-
vation, a second growth of trees rapidly springs up, which, without
care or attention, attain their giant size in half the time that would
be expected on the best lands in England.^'

than loose chalk. By the author of the * Body of Agriculture,' it is said
to be a clay mixed with sand." (Essay on Manures, ch. 1.)

" Loam, or that species of artificial soil into which the others are gene-
rally brought by the course of long cultivation." — " AVhere a soil is mode-
rately cohesive, less tenacious than clay, and more so than sand, it is known
by the name of loam. From its frequency, there is reason to suppose that
in some cases it might be called an 'original soil.'"^ [^Sinclair's Code of
Agriculture — chap. 1.]

" The word loam should be limited to soils containing at least one-third
of impalpable earthy matter, copiously effervescing with acids.^' \_Davy''s
Agricultural Chemistry — Lecture 4.] According to this definition by the
most scientific writer and highest authority in chemical agriculture, if we
except the small portion of shelly land, there is certainly not an acre of
natural loam between the sea-coast of Virginia and the Blue Ridge Moun-
tains— and very few even in the limestone region.

" By loam is meant any of the earths combined with decayed animal or
vegetable matter.^' \_Appe7idiz to Agr. Ghem. by George Sinclair.']

"Loam — fat unctuous earth — marl." \Johnson^s Dictionary, 8vo. ed.y
and also Walker' s."]

"Loam may be considered a clay of loose or friable consistency, mixed
with mica or isinglass, and iron ochre." \_Editor of American Farmer ^
(old series) vol. Hi., page 320.]

[* In this and the next following seven chapters (II. to IX. inclusive),
in which are set forth my peculiar views of the qualities of our soils, the
general absence and want of calcareous earth, the mode of action of cal-
careous manures, and, in general, the theory of fertilization, the entire
matter of the edition of 1832 has been scrupulously retained, without altera-
tion, other than in a few transpositions of matter and mei-ely verbal cor-
rections, which have not at all altered the purport. Whatever else has
been added, in later editions and the present, whether to the text or as
notes, will be designated by being enclosed in brackets, and will also, in
most cases, be marked with the date of the edition, or the writing, in which
such additional passages first appeared,— 1852.]

(34)

TIDE-WATER DISTRICT OF VIRGINIA. 35

If the foregoing description was met with in a ^ Journey through
Cabul/ or some equally unknown region^ no European reader would
doubt that such lands were fertile in the highest degree — and many
even" of ourselves would receive the same impression. Yet it is no
exaggerated account of the poorest natural soils in our own gene-
rally poor coTjntry, which are as remarkable for their producing
luxuriant growths of pines, and broom-grass, as for their unpro-
ductiveness in every cultivated or valuable crop. We are so ac-
customed to these facts, that we scarcely think of their strangeness ;
or of the impropriety of calling any land barren, which will pro-
duce a rapid or heavy growth of any one plant. Indeed, by the
rapidity of that growth (or the fitness of the soil for its production),
we have in some measure formed a standard of the poverty of the
soil.

With some exceptions to every general character, the tide-water
district of Virginia may be described as generally level, sandy,
poor, and free from any fixed rock, or any other than stones rounded
apparently by the attrition of water. On much the greater part
of the lands, no stone of any kind is to be found of larger size than
gravel. Pines of different kinds form the greater part of a heavy
cover to the silicious soils in their virgin state, and mix consider-
ably with oaks and other growth of clay land. Both these kinds
of soil, after being exhausted of their little fertility by cultivation,
and '' turned out" to recruit, are soon covered by young pines which
grow with vigour and luxuriance. This general description applies
more particularly to the ridges which separate the slopes on differ-
ent streams. The ridge lands are always level, and very poor —
sometimes clayey, more generally sandy, but stiff"er than would be
inferred from the proportion of silicious earth they contain, which
is caused by the fineness of its particles. Whortleberry bushes, as
well as pines, are abundant on ridge lands — and numerous shallow
basins are found, which are ponds of rain water in winter, but dry
in summer. None of this large proportion of our lands has paid
the expense of clearing and cultivation, and much the greater part
still remains under its native growth. Enough, however, has been
cleared and cultivated in every neighbourhood to prove its utter
worthlessness under common management. The soils of ridge
lands vary between sandy loam and ^.clayey loam. It is difficult to
estimate their general product under cultivation; but judging from
my own experience of such soils, the product may be from five
bushels of corn, or as much of wheat, to the acre on the most clayey
soils, to twelve bushels of corn, and less than three of wheat, on
the most sandy — if wheat were there attempted to be made.

The slopes extend from the ridges to the streams, or to the allu-
vial bottoms, and include the whole interval between neighbouring
branches of the same stream. This class of soils forms another

36 TIDE-WATER DISTRICT OF VIRGINIA.

great body of lands, of a higher grade of fertility, though still far
from valuable. It is generally more sandy than the poorer ridge
land, and when long cultivated, is more or less deprived of its soil,
by the washing of rains, on every slight declivity. The washing
away of three or four inches in depth exposes a sterile subsoil (or
forms a ^^galF^), which continues thenceforth bare of all vegetation.
A greater declivity of the surface serves to form gullies several feet
in depth, the earth carried from which covers and injures the ad-
jacent lower land. Most of this kind of land has been cleared
and greatly exhausted. Its virgin growth is often more of oak,
hickory, and dogwood, than pine ; but when turned out of cultiva-
tion, an unmixed growth of pine follows. Land of this kind in
general has very little durability. Its best usual product of corn
may be, for a few crops, eighteen or twenty bushels — and even as
much as twenty-five bushels, from the highest grade. Wheat is
seldom a productive or profitable crop on the slopes, the soil being
generally too sandy. When such soils as these are called rich or
valuable (as most persons would describe them), those terms must
be considered as only comparative ; and such an application of them
proves that truly fertile and valuable soils are very scarce in lower
Virginia.

Almost the only very rich and durable soils below the falls of
our rivers are narrow strips of high-land along their banks, and the
low-lands formed by the alluvion of the numerous smaller streams
which water our country. These alluvial bottoms, though highly
productive, are lessened in value by being generally too sandy, and
by the damcige they suffer from being often inundated by floods of
rain. The best high-land soils seldom extend more than half a
mile from the river's edge — sometimes not fifty yards. These ir-
regular margins are composed of loams of various qualities,* but all
highly valuable ; and the best soils are scarcely to be surpassed in
their original fertility, and durability under severe tillage. Their
nature and peculiarities will be again adverted to, and more fully
described hereafter.

The simple statement of the general course of tillage to which
this part of the country has been subjected, is sufl&cieut to prove
that great impoverishment of the soil has been the inevitable con-
sequence. The small portion of rich river margin was soon all
cleared, and was tilled without cessation for many years. The
^clearing of the slopes was next commenced, and 'is not yet entirely
completed. On these soils, the succession of crops was less rapid,
or, from necessity, tillage was sooner suspended. If not rich
enough for tobacco when first cleared (or as soon as it ceased to be
so), land of this kind was planted in corn two- or three years in
succession, and afterwards every second year. The intermediate
year between the crops of corn, the field was " rested'' under a

BARRENNESS OP TIDE-WATER DISTRICT. 37

crop of wheat, if it would produce four or five bushels to the acre.
If the sandiness, or exhausted condition of the soil, denied even
this small product of wheat, that crop was probably not attempted;
and, instead of it, or oats, the field was exposed to close grazing,
from the time of gathering one crop of corn to that of preparing
to plant another. No manure was applied, except on tluj tobacco
lots ; and this succession of a grain crop every year, and afterwards
every second year, was kept up as long as the field would produce
five bushels of corn to the acre. When reduced below that pro-
duct, and to still more below the necessary expense of cultivation,
the land was turned out to recover under a new growth of pines.
After twenty or thirty years, according to the convenience of the
owner, the same land would be again cleared, and put under similar
scourging tillage, which, however, would then much sooner end,
as before, in exhaustion. Such a general system is not yet every-
where abandoned ; and many years have not passed since such was
the usual course on almost every farm.

How much our country has been impoverished during the last
fifty years, cannot be determined by any satisfactory testimony.
But, however we may difi'er on this head, there are but few who
will not concur in the opinion, that [up to 1831] our system of
cultivation has been every year lessening the productive power of
our lands in general — and that no one county, no neighbourhood,
and but few particular farms, have been at all enriched since their
first settlement and cultivation. Yet many of our farming opera-
tions have been much improved and made more productive. Driven
by necessity, proprietors direct more personal attention to their
farms — better implements of husbandry are used — every process
is more perfectly performed — and, whether well or ill directed, a
spirit of inquiry and enterprise has been awakened, which before
had no existence.

Throughout the country below the falls of the rivers, and perhaps
thirty miles above, if the best land be excluded, say one-tenth, the
remaining nine-tenths will not yield an average product of ten
bushels of corn to the acre ; though that grain is best suited to our
soils in general, and far exceeds in quantity all other kinds raised.
Of course, the product of a large proportion of the land would fall
below this average. Such crops, in very many cases, cannot re-
munerate the cultivator. If our remaining wood-land could be at
once brought into cultivation, the gross product of the country
would be greatly increased ; but the nett product very probably
diminished ; as the general poverty of these lands would cause more
expense than profit to accompany their cultivation under the usual
system. Yet every year we are using all our exertions to clear
wood-land, and in fact seldom increase either nett or gross products
— because netirly as much old exhausted land is turned out of cul-
4

38 LOW PROFITS OF TIDE-WATER DISTRICT.

tivation as is substituted by tbe newly cleared. Sound calculations
of profit and loss would induce us even greatly to reduce the extent
of our present cultivation, in lower Virginia, by turning out and
leaving waste (if not to be improved), every acre that yields less
than the total cost of its tillage."^

No political truth is better established than that the population
of every country will increase, or diminish, according to its regular
supply of food. We know from the census of 1830, compared with
those of 1820 and 1810, that our population is nearly stationary,
and, in some counties, is actually lessening; and therefore it is
certain that [to 1830] our agriculture in general is not increasing
the amount of food, or the means of purchasing food — with all the
assistance of the new land annually brought under culture. In
these circumstances, a surplus population, with all its deplorable
consequences, is only prevented by the great current of emigration
which is continually flowing westward. No matter wha emigrates,
or with what motive — the enterprising or wealthy citizen who
leaves us to seek richer lands and greater profits, and the slave sold
and carried away on account of his owner's poverty — all concur in
producing the same result, though with very different degrees of
benefit to those who remain. If this great and continued drain
from our population was stopped, and our agriculture was not im-
proved, want and misery would work to produce the same results.
Births would diminish, and deaths would increase ; and hunger and
disease, operating here as in other countries, would keep down
population to that number that the average products of our agri-
cultural and other productive labour can feed, and supply with the
other necessary means for living.

A stranger to our situation and habits might well oppose to my
statements the very reasonable objection, that no man would, or
could, long pursue a system of cultivation of which the returns fell
short of his expenses, including rent of land, hire of labour, interest
on the necessary capital, &c. Very true ; if he had to pay those
expenses out of his profits, he would soon be driven from his farm
to a jail. But we own our land, our labourers, and stock; and
though the calculation of nett profit, or of loss, is precisely the same,
yet we are not ruined by making only two per cent, on our capital,

[* The foregomg description was written in 1826, and first published in
1831, and particular exceptions to the general correctness of the applica-
tion had been even then recently exhibited ; and, with the passage of every
year since, these exceptions have been becoming more numerous and more
important, and in a rapidly increasing ratio. These recent facts of im-
proved lands and increased production, as well as their peculiar causes,
will be treated of subsequently. The observations and deductions presented
in the remainder of this chapter were also of the same date as the forego •
ing statements, on which they are founded. (1842.) ]

FIVE GENERAL PROPOSITIONS. 39

provided we can manage to live on that income. If we live on
still less, we are actually growing richer (by laying tip a part of
our two per cent.), notwithstanding the most clearly-proved regular
loss on our farming.

Our condition has been so gradually growing worse, that we are
either not aware of the extent of the evil, or are in a great measure
reconciled by custom to profitless labour. No hope for a better
state of things can be entertained, until we shake off this apathy —
this excess of contentment, which makes no effort to avoid existing
evils. I have endeavouredr to expose what is worst in our situation
as farmers; if it should have the effect of arousing any of my
countrymen to a sense of the absolute necessity of some improve-
ment, to avoid ultimate ruin, I hope also to point out to some of
their number, if not to all, that the means for certain and highly
profitable improvements are completely within their reach.

CHAPTEH III.

THE DIFFERENT CAPACITIES OF SOILS FOR RECEIVINO
IMPROVEMENT.

As far as the nature of the subjects permitted, the foregoing
chapters have been merely explanatory and descriptive. The same
subjects will be resumed and more fully treated in the course of
the following general argument, the premises of which are the facts
and circumstances that have been detailed. The object of this
essay will now be entered upon ; and what is desired to be proved
will be stated in a series of propositions, which will now be pre-
sented at one view, and afterwards separately discussed in their
proper order.

Proposition 1. Soils naturally poor, and rich soils reduced to
poverty by cultivation, are essentially different in their powers of
retaining putrescent (or alimentary) manures; and, under like
circumstances, the fitness of any soil to be enriched by these ma-
nures is in proportion to the degree of its natural fertility.

2d. The natural sterility of the soils of lower Virginia is caused
by such soils being destitute of calcareous earth, and their being
injured by the presence and effects of vegetable acid.

3d. The fertilizing effects of calcareous earth are chiefly pro-
duced by its power of neutralizing acids, and of combining putrcs-

40 I\ATURAL FERTILITY.

cent manures with soils, between which there would otherwise ha
hut little if *ny ohemical attraction.*

- 4th. Poor and acid soils cannot be improved durably, or profit-
ably, by putrescent manures, without previously making such soils'
calcareous, and thereby correcting the natural defect in their con-
stitution.

5th. Calcareous manures will give to our worst soils a power of '
retaining putrescent manures, equal to that of the best — and will
cause more productiveness, and yield more profit, than any other
improvement practicable in lower Virginia.

Dismissing from consideration, for the present, all the others, I
shall proceed to maintain the

First Proposition. — Soils naturalli/ poor, and ricli soils reduced
to poverty hy cultivation, are essentially different in their poivers
of retaining putrescent (or alimentary) manures; and, under
like circumstances, the fitness of any soil to be enriched by these
manures is in proportion to the degree of its natural fertility.
The 7iatural fertility of a soil is not intended to be estimated by
the amount of its earliest product, when first brought under cultiva-
tion, because several temporary causes then operate either to keep
down or to augment the product. If land be cultivated immediately
after the trees are cut down, the crop is greatly lessened by the nu-
merous living roots, and consequent bad tillage — by the excess of
unrotted vegetable matter — and the coldness of the soil, from
which the rays of the sun had been so long excluded. . On the
other hand, if cultivation is delayed one or two years, the leaves
and other vegetable matters are rotted, and in the best state to sup-
ply food to plants, and are so abundant, that a far better crop will
be raised than could have been obtained before, or perhaps can be
again, without manure. For these reasons, the degree of natural
fertility of any soil should be measured by its products after these

* When any stibstance is mentioned as combining with one or more other
substances, as different manures with each other, or with soil, I mean that
a union is formed by chemical attraction, and not by simple mixture. 3Iiz-
tures are made by mechanical means, and may be separated in like manner ;
but combinations are chemical, and require some stronger chemical attrac-
tion, to take away either of the bodies so united.

When two substances combine, they both lose their previous peculiar
qualities, or neutralize them for each other, and form a third substance
different from both. Thus, if certain known proportions of muriatic acid
and pure or caustic soda be brought together, their strong attraction will
cause them to combine immediately. The strong corrosive acid quality
of the one, and the equally peculiar alkaline taste and powers of the other,
will neutralize or entirely destroy each other — and the compound formed is
egmmon table salt, the qualities of which are as strongly marked, but
totally different from those of either of its constituent parts.

SOILS NATURALLY RICH OR POOR. 41

temporary causes have ceased to act, which will generally take place
before the third or fourth crop is obtained. According, then, to
this definition, a certain degree of permanency in its early produc-
tiveness is necessary to entitle a soil to be termed naturally fertile.
It is in this sense that I deny to any poor lands, except such as
were naturally fertile, the capacity of being made rich by putres-
cent manures only.

The foregoing proposition would by many persons be so readily
admitted as true, that attempting to prove it would be deemed
entirely superfluous. But many others will as strongly deny its
truth, and can support their opposition by high agricultural
authorities.

General readers, who may have no connexion with farming, must
have gathered from the incidental notices in various literary and
descriptive works, that some, countries or districts that were noted
for their uncommon . fertility or barrenness as far back as any
accounts of them have been recorded, still retain the same general
character, through every change of culture, government, and even
of races of inhabitants. They know that, for some centuries at
least, there has been no change in the strong contrast between the
barrenness of Norway, Brandenburg, and the Highlands of Scot-
land, and the fertility of Flanders, Lombardy, and Valencia. Sicily,
notwithstanding its government is calculated to discourage* in
dustry, and production ^f every profitable kind, still exhibits that
fertility for which it was celebrated two thousand years ago. It
leems a necessary inference from the many statements of which
these are examples, that the labours of man have been but of little
avail in altering, generally or permanently, or in any marked de-
gree, the characters and qualities given to soils by nature.

Most of our experienced practical cultivators, through a different
course, have arrived at the same conclusion. Their practice has
taught them the truth of this proposition ] and the opinions thus
formed have profitably directed their most important operations.
They, are accustomed to estimate the worth of land by its natural
degree of fertility; and by the same rule they are directed on what
BoiiS to bestow their scanty stock of manure, and where to expect
exhausted fields to recover by rest, and their own unassisted powers.
But, content witii knowing the iic!:, this useful class of farmers
have never inquired for its caii^e ; iiud even f lieir opinions on this,
as on most other subjects, have not been communicated so as to
benefit other cultivators.

But if all literary men, who are not farmers, and all practical
cultivators, who seldom read, admitted the truth of my proposition,
it would avail but little for improving our agricultural operations;
and the only prospect of its being usefully disseminated is through
that class of farmers who have received their first opinions of im-

42 ERRONEOUS DOCTRINES OP WRITERS.

proving soils from books, and wliose subsequent plans and practices
have grown out of those opinions. If poor natural soils cannot be
durably or profitably improved by putrescent manures, this truth
should not only be known, but be kept constantly in view, by
every farmer who can hope to improve with success. Yet it is a
remarkable fact, that the difference in the capacities of soils for
receiving improvement has not attracted the attention of scientific
farmers ; and the doctrine has no direct and positive support from
the author of any treatise on agriculture, European or American,
that I have been able to consult. On the contrary, it seems to be
considered by all of them, that to collect and apply as much
vegetable and animal manure as possible, is sufficient to insure
profit to every farmer, and fertility to every soil. They do not tell
us that numerous exceptions to that rule will be found, and that
many soils of apparently good texture, if not incapable of being
enriched from the barn-yard, would at least cause more loss than
clear profit, by being improved from that source.

When it is assumed that the silence of every distinguished author
as to certain soils being incapable of being profitably enriched,
amounts to ignorance of the fact, or a tacit denial of its truth — ^it
may be objected that the exception was not omitted from either of
these causes, but because it was established and undoubted. This
is barely possible ; but even if such were the case, their silencg has
had all the ill consequences that could have grown out of a positive
denial of any exceptions to the propriety ol manuring poor soils.
Every zealous young farmer, who draws most of his knowledge and
opinions from books, adopts precisely the same idea of their di-
rections— and if he owns barren soils he probably throws away his
labour and manure for their improvement, for years, before experience
compels him to abandon his hopes, and acknowledge that his guides
have led him only to failure and loss. Such farmers as I allude
to, by their enthusiasm and spirit of enterprise, are capable of
rendering the most important • benefits to agriculture. Whatever
niay be their impelling motives, the public derives nearly all the
benefit of their successful plans ; and their far more numerous mis-
directed labours, and consequent disappointments, are productive of
national, still more than individual loss. The occurrence of only
a few such mistakes, made by reading farmers, will serve to acquit
me of combating a shadow — and there are few of us who cannot
recollect some such examples.

But if the foregoing objection has any weight in justifying Euro-
pean authors in not naming this exception, it can have none for
those of our own country. If it be admitted that soils naturally
poor are incapable of being enriched with profit, that admission
must cover three-fourths of all the high land in*the tide-water dis-
trict. Surely no one will contend that so sweeping an exception

DOCTRINE OP "ABATOR.^* 43

was silently understood by the author of ^ Arator^ as qualifying his
exhortations to improve our lands; and if no such exception were
intended to be made, then will his directions for enriching soils and
his promises of reward be found equally fallacious, for the greater
portion of the country which his work was especially intended to
benefit. The omission of any such exception, by the writers of the
United States, is the more remarkable, as the land has been so
recently brought under cultivation, that the original degree of
fertility of almost every farm may be known to its owner, and com-
pared with the after progress of exhaustion or improvement.

Many authorities might be adduced to prove that I have correctly
stated what is the fair and only inference to be drawn from agricul-
tural books, respecting the capacity of poor soils to receive improve-
ment. But a few of the most strongly marked passages in ' Arator'
will be fully sufiicient for this purpose. The venerated author of that
work was too well acquainted with the writings of European agricul-
turists, to have mistaken their doctrines in this important particular.
A large portion of his useful life was devoted to the successful
improvement of exhausted, but originally fertile lands. His instruc-
tions for producing similar improvements are expressly addressed
to the cultivators of the eastern parts of Virginia and North Caro-
lina, and are given as applicable to all our soils, without exception.
Considering all these circumstances, the conclusions which are
evidently and unavoidably deduced from his work, may be fairly
considered, not only as supported by his own experience, but as
concurring with the general doctrine of improving poor soils, main-
tained by previous writers.

At page 54, third edition of 'Arator/ ^^ enclosing^' (i. e. leaving
fields to receive their own vegetable cover, for their improvement,
during the years of rest) "is said to be " the most powerful means
of fertilizing the earth^' — and the process is declared to be rapid,
the returns near, and the gain great.

At page 61 are the following passages : " If these few means of
fertilizing the country (corn-stalks, straw, and animal dung) were
skilfully used, they would of themselves sufiice to change its state
from sterility to fruitfulness.^' — ^' By the litter of Indian corn, and
of small grain, and of penning cattle, managed with only an inferior
degree of skill, in union with enclosing, I will venture to affirm that
a farm may in ten years be made to double its produce^ and in
twenty to quadruple it.''

No opinions could be more strongly or unconditionally expressed
than these. No reservation or exception is made. I may safely
appeal to each of the many hundreds who have attempted to obey
these instructions, to declare whether any one considered his own
naturally poor soils excluded from the benefit of these promises — or

44 EVIDENCE OP FACTS.

whether a tithe of the promised benefit was realized upon trial on
any farm having generally such soils.

In a field of mine that has been secured from grazing since 1814,
and cultivated on the mild four-shift rotation, the produce of a
marked spot has been measured every fourth year (when in corn)
since 1820. The difference of product has been such as the dif-
ferences of season might have caused — and the last crop (in 1828)
was worse than those of either of the two preceding courses.
There is no reason to believe that even the smallest increase of
productive power had taken place in all the preceding fourteen
years. [Nor has there been, to 1841, in the apparent products of
this ground, any manifestation that there has been any more of
subsequent than of previous improvement, from the vegetable
manurings furnished by its growth. 1842.]

[A still more striking proof, because of the much larger scale, as
well as long continuance of the experiment, has been very recently
(in 1842), as well as in former times, mentioned to me, as confirm-
ation of my views in this respect. Col. George Blow, of Sussex,
a highly respectable gentleman and intelligent and observant
farmer, had adhered for nearly thirty years to Taylor's " enclosing
system," and with a very mild rotation, on a farm of 600 arable
acres, of sandy soil, and originally poor ; and had taken but one
crop (corn) in every three years. A few spots only of better
quality (the sites of old buildings^ &c.) were put in wheat or oats
after the corn; the great body of the land having had regularly
two years in three to rest, and to manure itself by its volunteer
growth of weeds and grass. Very little grazing, and that but
rarely, was permitted. There could have been no material mistake
as to the general products and results ; and the proprietor is confi-
dent that the land has not improved in production in all this long
time. Yet, on soil diff"erently constituted. Col. Blow has improved
and increased the products, rapidly and profitably. These two
facts, though observed more particularly and for longer time than
any others known, agree with, and are but confirmatory of others
presented to some extent on almost every farm in the tide-water
region of Virginia. 1842.]

It is far from my intention, by these remarks, and statements of
facts, to deny the propriety, or to question the highly beneficial
results, of applying the system of improvement recommended by
' Arator,' to soils originally fertile. On the contrary, it is as much
my object to maintain the facility of restoring to worn lands their
natural degree of fertility, by vegetable applications, as it is to
deny the power of exceeding that degree, however low it may have
been. "

One more quotation will be offered, because its recent date and
the source whence it is derived furnish the best proof that it is still

OPPOSING DOCTRINE. 45

the received opinion, among agricultural writers, tliat all soils may-
be profitably improved by putrescent manures. An article in the
' American Farmer,' of October 14th, 1831, on ^^ manuring large
farms," by the editor (Gr. B. Smith), contains the following ex-
pressions. "By proper exertions, every farm in the United States
can be manured with less expense than the surplus profits arising
from the manure would come to. This we sincerely believe, and
we have arrived at this conclusion from long and attentive observa-
tion. We never yet saw a farm that we could not point to means
of manuring, and bring into a state of high and profitable cultiva-
tion at an expense altogether inconsiderable when contrasted with
the advantages to be derived from it." The remainder of the
article shows that putrescent manures are principally relied on to
produce these effects ; marsh and swamp mud are the only kinds
referred to that are not entirely putrescent in their action ; and mud
certainly cannot be used to manure every farm. Mr. Smith having
been long the conductor of a valuable agricultural journal, as a
matter of course, is extensively acquainted with the works and
opinions of the best writers on agriculture; and therefore, his
advancing the foregoing opinions, as certain and undoubted, is as
much a proof of the general concurrence therein of preceding
writers, as if the same had been given as a digest of their pre-
cepts.*

Some persons will readily admit the great difference in the capa-
cities of soils for improvement, but consider a deficiency of clay
only to cause the want of power to retain manures. The general
excess of sand in our poor lands might warrant this belief in a
superficial and limited observer. But though clay soils are more
rarely met with, they present, in proportion to their extent, full as
much poor land. The most barren and worthless soils in the
county of Prince George are also the &*tifiest.. A poor clay soil will
retain manure longer than a poor sandy soil — but it will not the
less certainly lose, its acquired fertility at a somewhat later period.
When it is considered that a much greater quantity of manure is
required by elay soils, it may well be doubted whether the tem-

[^ Thougli not then known to me, and probably to few if any others in
America, there was then in print the expression of the opinion which I
have announced and maintained aboye. This exception I subsequently met
wit"h, and republished the article in the Farmer's Register (Vol. iv. p, 335.)
It was a communication from the excellent practical farmer, William Daw-
son, of Scotland, to the Farmer's Magazine, published in Edinburgh. In
this communication, the writer, and, so far as I know, he only, before
myself, asserts opinions which approach very nearly to the doctrine above
maintained, of the incapacity of naturally poor soils for being profitably
or durably improved by putrescent manures alone — and also their newly
acquired fitness for being enriched after having been limed.]

46 LIMIT TO IMPROVEMENT OE SOILS.

porary improvement of the sandy soils would not be attended with
more profit — or, more properly speaking, with less actual loss.

It is true that the capacity of a soil for improvement is greatly
affected by its texture, shape of the surface, and its supply of
moisture. Dry, level, or clay soils, will retain manure longer than
the sandy, hilly, or wet. But however important these circum-
stances may be, neither the presence nor absence of any of them
can cause the essential differences of capacity for improvement.
There are some rich and valuable soils with either one or more of
all these faults — and there are other soils the least capable of re-
ceiving improvement, free from objections as to their texture,
degree of moisture, or inclination of their surface. Indeed the
great body of our poor ridge lands are more free from faults of this
-kind, than soils of far greater productiveness usually are. Unless
then some other and far more powerful obstacle to improvement
exists, why should not all our wood-land be highly enriched, by the
thousands of crops of leaves which have successively fallen and
rotted there ? Notwithstanding this vegetable manuring, which
infinitely exceeds all that the industry and patience of man can
possibly equal, most of our wood-land remains poor ; and this one
fact (which at least is indisputable) ought to satisfy all of the
impossibility of enriching such soils by putrescent manures only.
Some few acres may be highly improved, by receiving all the
manure derived from the offal of the whole farm — and entire farms,
in the neighbourhood of towns, may be kept rich by continually
applying large quantities of purchased manures. But no where can
a farm be found, which has been improved beyond its original
fertility, by means of the vegetable resources of its own arable
fields. If this opinion is erroneous, nothing is easier than to prove
my mistake, by adducing undoubted examples of such improve-
ments having been made.

But a few remarks will suffice on the capacity for improvement
of worn lands, which were originally fertile. With regard to these
soils, I have only to concur in the received opinion of their fitness
for durable and profitable improvement by putrescent manures.
After being exhausted by cultivation, they will recover their pro-
ductive power, by merely being left to rest for a sufficient time,
and receiving the manure made by nature, of the weeds and other
plants that grow and die upon the land. Even if robbed of ^ the
greater part of that supply, by the grazing of animals, a still longer
time will serve to obtain the same result. The better a soil was at
fii'st, the sooner it will recover by these means, or by artificial
manuring. On soils of this kind, the labours of the improving
farmer meet with certain success and full reward ; and whenever
we hear of remarkable improyements of poor lands by putrescent

TROPER MODE OF INVESTIGATION. 47

manures, further inquiry will show us that these poor lands had
once been rich.

The continued fertility of certain countries, for hundreds or even
thousands of years, does not prove that the land could not be, or
had not been, exhausted by cultivation; but only that it was slow
to exhaust and rapid in recovering; so that whatever repeated
changes may have occurred in each particular tract, the whole
country taken together always retained a high degree of productive-
ness. Still the same rule will apply to the richest and the poorest
soils — to wit, that each exerts strongly a force to retain as much
fertility as nature gave to it — and that when worn and reduced,
each kind may easily be restored to its original state, but cannot be
raised higher, with either durability or profit, by putrescent ma-
nures, whether applied by the bounty of nature^ or the industry
of man.

CHAPTER ly.

EFFECTS OF THE PRESENCE OF CALCAREOUS EARTH IN SOILS.

Proposition 2. — The natural sterility of tlie soils of lower Virginia
is caused hy such soils being destitute of calcareous earth, and
their being injured ly the presence and effects of vegetable acid.

The means which would appear the most likely to lead to the
causes of the different capacities of soils for improvement is to
inquire whether any known ingredient or quality js-^lways to be
found belonging to improvable soils, and never to the unim-
provable— or which always accompanies the latter, and never the
former kind. If either of these results can be obtained, we will
have good ground for supposing that we have discovered the general
cause of fertility, in the one case, or of barrenness, in the other;
and it will follow that, if we can supply to barren soils the deficient
beneficial ingredient — or can destroy that which is injurious to
them — their incapacity for receiving improvement will be removed.
All the common ingredients of soils, as sand, clay, or gravel — and
such qualities as moisture or dryness — a level, or a hilly surface —
however they may affect the value of soils, are each sometimes
found exhibited, in a remarkable degree, in both the fertile and the
sterile. The abundance of putrescent vegetable matter might well
be considered the cause of fertility, by one who judged only from
lands long under cultivation. But though vegetable matter in
sufficient quantity is essential to the existence of fertility, yet will

48 FERTILITY OF SHELLY SOILS.

this substance also be found inadequate for the cause. Vegetable
matter abounds in all rich land, it is admitted } but it has also been
furnished by nature, in quantities exceeding all computation, to the
most barren soils known.

"" But there is one ingredient of which not the smallest proportion
can be found in any of our poor soils, and which, wherever found,
(and not in great excess), indicates a soil remarkable for natural
and durable fertility. This is calcareous earth, or carbonate of
lime. These facts alone, if sustained, will go far to prove that this
earth is the cause of fertility, and the cure for barrenness.

On some part of most farms touching tide-water, either mussel
or oyster shells are found mixed with the soil. Oyster shells are
confined to the lands on salt water, where they are very abundant,
and sometimes extend through large fields. Higher up the rivers,
mussel shells only are to be seen thus deposited by nature, or by
the aboriginal inhabitants, and they decrease as we approach the
falls of the rivers. The proportion of shelly land in the counties
highest on tide-water is very smkll ; but the small extent of these
spots does not prevd' , ] iit rather aids, the exhibition of the pecu-
liar qualities of sucli scils. ^p'^i.^ of ^helly iai^l, not exceeding a
few acres in extent, could not well have been cT:ltiTated dif^rently
from the balance of the fielJi of which tli^^y Kimed parls — :\vd
therefore they can be better compared with the worse soils rii ':r
like treatment. Every acre of shelly land is, cr has been, remi rk-
able for its richness, and still more for its durability. There are
few farmers among us who have not heard described tracts of shelly
soil on Nansemond and York rivers, which are celebrated for their
long resistance of the most exhausting course of tillage, and which
still remain fertile, notwithstanding all the injurj^ which they must
have sustained from their severe treatment. We are told that on
some of these lands, corn has been raised every Successive year,
without any help from manure, for a longer time than the owners
could remember, or could be informed of correctly. But without
relying on any such remarkable cases, there can be no doubt that
every acre of our shelly land has been at least as much tilled, and
as little manured, as any in the country ; and that it is still the
richest and most valuable of all our old cleared lands.

The fertile but narrow strips, along the banks of our rivers
(which form the small portion of our high-land of first-rate quality),
seldom extend far without exhibiting spots in which shells are
visible, so that the eye alone is sufficient to prove the soil of such
places to be calcareous. The similarity of natural growth, and of
all other marks of character, are such, that the observer might very
naturally infer that the former presence of shells had given the
same valuable qualities to all these soils — but that they had so
generally rotted, and been incorporated with the other earths, that

NATURAL GROWTHS OF DIFFERENT SOILS. 49

tliey remained visible only in a few places, wliere they had been
most a'bundant. The accuracy of this inference will hereafter be
examined.

The natural growth of the shelly soils (and of those adjacent of
similar value) is entirely different from that of the great body of
our lands. Whatever tree thrives well on the one, is seldom found
on the other class of soils — or, if found, it shows plainly, by its
imperfect and stunted condition, on how unfriendly a soil it is
placed. To the rich river margins are almost entirely confined the
black or wild locust, hackberry or sugar-nut tree, and papaw. The
locust is with great difficulty eradicated, or the newer growth of it
kept under on cultivated lands j and from the remarkable rapidity
with which it springs up and increases in size, it forms a serious
obstacle to the cultivation of knd on the river banks. Yet on the
wood-land only a mile or two from the river, not a locust is to be
seen. On shelly soils, pines and broom-grass [^Andropogon scopa-
7'ius\ cannot thrive, and are rarely able to maintain even the most
sickly growth.

Some may say that these striking differences of growth do not
so much show a difference in the constitution of the soils, as in
their state of fertility ; or that one class of the plants above named
delights in rich, and the other in poor land. No plant prefers poor
to rich soil — or can thrive better on a scarcity of food, than with
an abundant supply. Pine, broom-grass, and sheep-sorrel, delight
in a class of soils that are generally unproductive — but not on
account of their poverty; for all these plants show, by the greater
or less vigour of their growth, the abundance or scarcity of vegetable
matter in the soil. But on this class of soils, no quantity of
vegetable manure could make locusts flourish, though they will
grow rapidly on a calcareous hill-side, from which all the soil
capable of supporting other ordinary plants has been washed away.

In thus describing and distinguishing soils by their gi'owth, let
me not be understood as extending these rules, without exception,
to other soils and climates than our own. It is well established
that changes of kind in successive growths qf timber have occurred
in other places, without any known cause; and a difference of
climate may elsewhere produce effects, which here would indicate
a change of soil.

Some rare apparent exceptions to the general fertility of shelly
lands are found where the proportion of calcareous earth is in great
excess. Too much of this ingredient causes even a greater degree
of sterility than its total absence. This cause of barrenness is
very common in France and England (on chalk soils), and very
exlensive tracts are not worth the expense of cultivation, or im-
provement. The few small spots that are rendered barren here are
seldom (if ever) so affected by the excess of oyster or mussel shells

50 ERRONEOUS VIEWS OF AUTHORS.

in the soil. These effects generally are caused Iby beds of fossil
sea-shells, which in some places reach the surface, and are* thus
exposed to the plough. These spots (which are the only super-
calcareous or chalky soils of this region) are not often more than
thirty feet across, and their nature is generally evident to the eye }
and if not, is so easily determined by chemical tests, as to leave no
reason for confounding the injurious and beneficial effects of cal-
careous earth. This exception to the general fertilizing effect of
this ingredient of our soils would scarcely require naming, but to
mark what might be deemed an apparent contradiction. But this
exception, and its cause, must be kept in mind, and considered as
always understood and admitted throughout all my remarks, and
which therefore it is not necessary to name specially, when the
general qualities of calcareous earth are spoken of. [After all, this
exception is only in appearance, as it is found only in super-cal-
careous soils, and never in any soil in which calcareous earth is not
so abundant as to form a physical material. — 1849.]

In the beginning of this chapter, I advanced the important fact
that none of our poor soils contain naturally the least particle of cal-
careous earth. So far, this is supported merely by my assertion — and
all those who have studied agriculture in books will require strong
proof before they can give credit to the existence of a fact, which
is either unsupported, or indirectly denied, by all written authority.
Others, who have not attended to such descriptions of soils in
general, may be too ready to admit the truth of my assertion —
because, not knowing the opinions on this subject heretofore re-
ceived and undoubted, they would not be aware of the importance
of their admission.

It is true that no author has said expressly that every soil con-
tains calcareous earth. Neither perhaps has any one stated that
every soil contains some silicious or aluminous earth. But the
manner in which each one has treated of soils and their constituent
parts, would cause their readers to infer that neither of these three
earths is ever entirely wanting — or at least that the entire absence
of the calcareous is as rare as the absence of silicious or aluminous
earth. Nor are we left to gather this opinion solely from indirect
testimony, as the following examples, from the highest authorities,
will prove. Davy says, "four earths generally abound in soils, the
aluminous, uie silicious, the calcareous, and the magnesian;"* and
the soils of which he states the constituent parts, obtained by
chemical analysis, as well as those reported by Kirwan, and by
Young, all contain some proportion (and generally a large propor-
tion) of calcareous earth.f Kirwan states the component parts of

* Davy's Agr. Chem., Lecture 1.

f Agr. Chem., Lect. 4. — Kirwan on Manures;— and Young's Prize Essay
on Muuui-eb.

ASSERTIONS OF CALX IN SOIL BEING USUAL. 51

a soil wliicli contained tliirty-one per cent, of calcareous earth, and
he supposes that proportion neither too little nor too much.*
Young mentions soils of extraordinary fertility containing seventeen
and twenty per cent., besides others with smaller proportions of
calcareous earth — and says that Bergman found thirty per cent.
in the best soil he examined. f liozier speaks still more strongly
for the general diffusion and large proportions of this ingredient
of soils. In his general description of earths and soils, he gives
examples of the supposed composition of the three grades of soils
which he designates by the terms richj good, and middling soils; to
the first class he assigns a proportion of one-tenth, to the second,
one-fourth, and to the last, one-half of its amount of calcareous
earth. The fair interpretation of the passage is that the author
considered these large proportions as general, in France — and he
gives no intimation of any soil entirely without calcareous earth. J

The position assumed above, of the general or universal concur-
rence of former European authors in the supposed general presence
of calcareous earth in soils, could be placed beyond dispute by ex-
tracts from their publications. But this would require many and
long extracts, too bulky to include here, and which cannot be fairly
abridged, or exhibited by a few examples. No author says directly,
indeed, that calcareous earth is present in all soils; but its being
always named as one of the ingredients of soils in general, and no
cases of its absolute deficiency in tilled lands being directly stated,
amount to the declaration that calcareous earth is very rarely, if
ever, entirely wanting in any soil. We may find enough directions
to apply calcareous manures to soils that are deficient in that in-
gredient ; but that deficiency seems to be not spoken of as absolute,
but relative to other soils more abundantly supplied. In the same
manner, writers on agriculture direct clay, or sand, to be used as
manure for soils very deficient in one or the other of those earths;
but without meaning that any soil under cultivation can be found
entirely destitute of sand or of clay. My proofs from general
treatises would therefore be generally indirect ; and the quotations

* I^jrwan on Manures, article *' Clayey Loam."

f Young's Essay on Manures.

J " Composition of soils. Examples of the various composition of soils:
Rich soil; silicious earth, 2 parts ; aluminous, 6 ; calcai'eous, 1 ; vegeta-
ble earth, [humus'] 1 ; in all, 10 parts. Good soil — silicious, 3 parts ;
aluminous, 4; calcareous, 2|; vegetable earth, J of 1 part; in all, 10
parts, saddling soil [sol mediocre ;] silicious, 4 parts; aluminous, 1; cal-
careous, 5 parts, less by some atoms of vegetable earth ; in all, 10 parts.
We see that it is the largest proportion of aluminous earth that constitutes
the greatest excellence of soils ; and we know that independently of their
harmony of composition, they require a sufficiency of depth." — Translated,
from" the article ^' Tcn-cs,^' in the "Cours Complet d' Agriculture Pratique,
etc. par I'Abbe llozicr," 1815.

52 CONCURRINa AMERICAN AUTHORITIES.

necessary to exhibit them would show what had not been said,
rather than what had — and that they did not assert the absence of
calcareous earth, instead of directly asserting its universal presence.
Extracts for this purpose, however satisfactory, would necessarily
1)6 too voluminous, and it is well that they can be dispensed with.
Better proof, because it is direct, and more concise, will be furnished
by quoting the opinions of a few agriculturists of our own country,
who were extensively acquainted with European authors, and have
evidently drawn their opinions from those sources. These quota-
tions will not only show conclusively that their authors consider
the received European doctrine to be that all soils are more or less
calcareous — but also, that they apply the same general character to
the soils of the United States, without expressing a doubt or naming
an exception. These writers, as all who have heretofore written
of soils in this country, havejittered but the echoes of preceding
English general descriptions of soils. They seem not to have sus-
pected that any very important difference existed in thi* respect
between the soils of England and of this country ; and certainly not
one had made the slightest investigation by any attempt at chemical
analysis, to sustain the false character thus given to our soils.

1. From a "Treatise on Agriculture'' (ascribed to General
Armstrong), published in the American Farmer. \Yol. i. page
153.]

"Of six or eiglit substanc&s, which chemists have denominated earths,
four are loidely and abundantly diffused, and form the crust of our globe.
These are silica, alumina, lime, and magnesia." — " In a pure or isolated
state, these earths are wholly unproductive ; but when decomposed and
mixed, and to this mixture is added the residuum of dead animal or vege-
table matter, they become fertile, and take the general name of soils, and
are again denominated after the earth that most abounds in their composi-
tion respectively."

2. Address of R. H. Rose to the Agricultural Society of Susque-
hanna. [Am. Far. Vol. ii. p. 101.]

" Geologists suppose our earth to have been masses of rock of various
kinds, but principally silicious, aluminous, calcareous, and magnesian —
from the gradual attrition, decay, and mixture of which, together with an
addition of vegetable and animal matter, is formed the soil ; and this is
called sandy, clayey, calcareous, or magnesian, according as the particular
primitive material preponderates in its formation."

3. Address of Robert Smith to the Maryland Agricultural So-
ciety. \_Am. Far. Vol. iii. p. 228.]

<« The soils of our country are in general clay, sand, gravel, clayey

loam, sandy loam, and gravelly loam. Clay, sand, and gravel, need no
description, &c." — ^'■Clayey loam is a compound soil, consisting of clay
and sand or gravel, with a mixture of calcareous matter, and in which clay
is predominant. Sandy or gravelly loam is a compound soil, consisting of
sand or gravel and clay with a mixture of calcareous matter, and in which
sand or gravel is predominant."

CALCAREOUS SOILS SUPPOSED COMMON. 53

The first two extracts merely state tlie geological theory of the
formation of soils, which is received as correct by the most eminent
agriculturists of Europe. How far it may be supported or opposed
by the actual constitution and lumber of ingredients of European
soils, is not for me to decide, nor is the consideration necessary to
my subject. But the adoption of this general theory by American
writers, without excepting American soils, is an indirect, but com-
plete application to them of the same character and composition.
The writer last quoted states positively, that the various loams
(which comprise at least nineteen twentieths of our soils, and I pre-
sume also of the soils of Maryland) contain calcareous matter.
The expression of this opinion by Mr. Smith is sufficient to prove
that such was the fair and plain deduction from his general reading
on agriculture, from which source only could his opinions have been
derived. If the soils of Maryland are not very unlike those of
Virginia, I will venture to assert, that not one in a thousand of all
the clayey, sandy, and gravelly loams, contains the smallest propor-
tion of carhonate of lime — and that not a single specimen of cal-
careous soil can be found, between the falls of the rivers and the
most eastern body of limestone.

But though the direct testimony of European authors, as cited
in a foregoing page, concurs with the indirect proofs referred to
since, to induce the belief that soils are very rarely destitute of cal-
careous earth, yet statements may be found of some particular soils
being considered of that character. These statements, even if
presented by the authors of general treatises, would only seem to
present exceptions to their general rule of the almost universal
diffusion of calcareous earth in soils. But, so far as I know, no
such exceptions are named in the descriptions of soils in any general
treatise, and therefore have not the slightest influence in contradict-
ing or modifying their testimony on this subject. It is in the
description of soils of particular farms, or districts, that some such
statements are made ; and even if no such examples had been men-
tioned, they would not have been needed to prove the existence, in
Europe, of some soils, like most of ours, destitute of calcareous
earth. These facts do not oppose my argument. I have not
asserted (nor believed, since endeavouring to investigate this sub-
ject), that there were not soils in Europe, and perhaps many exten-
sive districts, containing no calcareous earth. My argument merely
maintains, that these facts would not be inferred, but the contrary,
by any general and cursory reader of the agricultural treatises of
Europe with which we are best acquainted. It has not been my
purpose to inquire as to the existence, or extent, of soils of this
kind in Europe. But judging from the indirect testimony furnished
by accounts of the mineral and vegetable productions, in general
descriptions of different countries, I would infer that soils having
6*

54 VIRGINIAN SOILS NOT CALCAREOUS.

no calcareous earth were often found in Scotland and the northern
part of Grermany, and that they were comparatively rare in England
and France.

f~ With my early impressions of the nature and composition of
soils, derived in like manner from tlie general descriptions given in
books, it was with surprise, and some distrust, that, when first

, attempting to analyze soils, in 1817, 1 found most of the specimens
entirely destitute of calcareous earth. The trials were repeated
with care and accuracy, on soils from various places, until I felt
authorized to assert, without fear of contradiction, that no naturally
poor soil, below the falls of the rivers, contains the smallest propor-
tion of calcareous earth. Nor do I believe that any exception to
this peculiarity of constitution can be found in any poor soil above
the falls ; but though these soils are far more extensive and im-
portant in other respects, they are beyond the district within the
limits of which I propose to confine my investigation.

These results are highly important, whether considered merely
as serving to establish my proposition, or as showing a radical
diiference between most of our soils, and those of the best cultivated
parts of Europe. Putting aside my argument to establish a par-
ticular theory of improvement, the ascertained fact of the universal
absence of calcareous earth in our poor soils leads to this conclusion,
that profitable as calcareous manures have been found to- be in
countries where the soils are generally calcareous in some degree,
they must be far more so on our soils that are quite destitute of
that necessary earth.*

[■'^ Since the first and even the last edition (1842) containing the above
deductions, the later agricultural chemists have removed much of the ob-
Bcurity before resting upon the calcareous character of European soils.
Two recent European works have been republished in the United States,
"which, on soils and calcareous manures especially, are more full and satis-
factory than any which had previously reached me. One is Boussingault's
" Rui-al Economy, in its relations with Chemistry, &c.,&c." This volume
was first published in this country in 1845 (by Appleton, & Co., N. Y.), from
the English translation and first edition. There is no date given to show
the time of publication of the original work in French, nor of the English
translation. But both were manifestly very recent; and probably neither
had been introduced or was accessible in this country before the American
edition appeared. As there is contained a reference to analyses of all the
crops made in 1841 . on the author's farm, in Vhich "long and tedious
labour" he "spent nearly a whole year," the original work could not have
been printed before the close of 1842, even if so early. The author, be-
sides being one of the most profound and able of modern chemists, and
who has directed much research to agricultural chemistry, was also a prac-
tical farmer, on a scale of operations sufficient to inform him how to pro-
perly direct his scientific investigations. Therefore, many of his subjects
and reported results are full^f instruction, and doubtless are to be relied
on as among the latest and most certain lights and truths yet derived from
applying chemistry to agi'iculture. The other work referred to above is

CHAPTER V.

RESULTS OF THE CHEMICAL EXAMINATIONS OF VARIOUS SOILS.

Proposition 2 — continued.

The certainty of any results of cliemical analysis would bo
doubted by most persons who have paid no attention to the means
employed for such operations ; and their incredulity will be the
more excusable, when such results are reported by one knowing
very little of the science of chemistry, and whose limited know-
ledge was gained without aid or instruction, and was sought solely
with the view of pursuing this investigation. Appearing under
such disadvantages, it is therefore the more incumbent^ on me to
show my claim to accuracy, or to so explain my method as to ena-

Jolinston's "Lectures on the Applications of Chemistry and Geology to
Agriculture," which was first published, complete in four parts, in London
in 1844. But as the e^irlier parts had been published in succession, I had
been able to see the first three at the close of 1843. The third part con-
tains the author's views and compilation of facts, chemical and agricultural,
of lime, as a constituent of soils and as manure. On these subjects, he is
more full of information than any or all preceding authors, because able to
draw from, compare, and decide upon the views of all his predecessors,
with the aid of the latest information as to European scientific research
and agricultural practices and results — and which advantages seem tohave
been used generally with ability and discretion.

It appears from both Boussingault's and Johnston's works, thajt the new
and still very defective science of agricultural chemistry no longer labours
under some of the grossest defects and errors which Avere indirectly and
justly charged in my remarks above ; or is liable to the formerly just
censure there indicat<?d, as will appear in the course of this essay. It is not
now left to be inferred, as before, that all or nearly all soils of England
and France contain carbonate of lime; and the errors of the process of
analyzing soils, used by Davy, and all other chemists, previous to a very
recent time, are pointed out, which errors led to the erroneous conclusion
that carbonate of lime is almost universally present in soils. These two
authors state many particular soils, as well as classes of soils by inference,
which contain not a trace of lime in the state of carbonate, as I had before
declared, in opposition to all the then existing authority, to be the case
with nearly all the soils of our Atlantic states. But still, after removing
this obscurity, it appears manifest from the many reported contents of
soils given by Boussingault, Johnston, and Liebig, that soils containing
carbonate of lime, and usually in large proportions, are very general in
Europe, so far as investigation has gone ; in this respect confirming my
own previous inferences, as stated above.

Some of the statements of these latest and ablest authorities, which now
offer cbnfirnuHory testimony for my foi'hierly unsupported and novel
opinions, will be quotoii in notes, or otherwise, on proper occasions. — 1849.]

(55)

56 MODE OP TESTING THE PRESENCE OP CALX.

He others to detect its errors, if any exist. To analyze a specimen
of soil completely, requires an amount of scientific acquirement
and practical skill to which I make no pretension. But merely to
ascertain the absence of calcareous earth (or carbonate of lime),
or, if present, to find its quantity, requires but little skill, and less
Bcienfee.

The methods recommended by different agricultural chemists for
ascertaining the proportion of calcareous earth in all soils, agree in
all material points. Their process will be described, and made as
plain as possible. A specimen of soil of convenient size is dried,
pounded, and weighed, and then thrown into muriatic acid diluted
with three or four times its quantity of water. The acid combines with,
and dissolves the lime of the calcareous earth, and its other ingre-
dient, the carbonic acidj being disengaged, rises through the liquid
in the form of gas, or air, and escapes with effervescence. After
the mixture has been well stirred, and has stood until all effer-
vescence is over (the fluid still being somewhat acid to the taste, to
prove that enough acid had been used, by some excess being left),
the whole is poured into a piece of blotting paper, folded so as to
fit within a glass funnel. The fluid containing the dissolved lime
passes through the paper, leaving behind the clay and silicious
sand, and any other solid matter ; over which, pure water is poured
and passed off several times, so as to wash off all remains of the
dissolved lime. These filtered washings are added to the solution,
to all of which is then poured a solution of carbonate of potash.
The two dissolved salts thus thrown together (muriate of lime,
composed of muriatic acid and lime, and carbonate of potasliy com-
posed of carbonic acid and potash), immediately decompose each
other, and form two new combinations. The muriatic acid leaves
the lime, and combines with the potash, for which it has a stronger
attraction — and the muriate of potash thus formed, being a soluble
salt, remains dissolved and invisible in the water. The lime and
carbonic acid being in contact, when let loose by their former part-
ners, instantly unite, and form carbonate of lime, or calcareous
earth, which, being insoluble, falls to the bottom. This precipitate
is then separated by filtering paper, is washed, dried and weighed,
and thus shows the proportion of carbonate of lime contained in
the soil.*

In this process, the carbonic acid which first composed part of
the calcareous earth, escapes into the air, and another supply is
afterwards furnished from the decomposition of the carbonate of
potash. But this change of one of its ingredients does not alter
the quantity of the calcareous earth, which is always composed of

* More full directions for th^ aaalysis of soils may be fotAid in Kirwan's
Essay on Manures, llozier's Cours Complet, &c., and Davy's Agricultural
Chemistry.

' TESTING THE PRESENCE OP CALX. • 5,7,

<

certain invariable proportions of its two component parts; and
when all the lime has been precipitated as above directed, it will
necessarily be combined with precisely its first quantity of carbonic
acid.

This operation is so simple, and the means for conductipg it so
easy to obtain, that it will generally be the most convenient mode
for finding the proportion of calcareous earth in those manures
that are known to contain it abundantly, and where an error of a
few grains cannot be very material: But if a very accurate result
is necessary, this method will not serve, on account of several
causes of error which always occur. Should no calcareous earth be
present in a soil thus analyzed, the muriatic acid will take up a
small quantity of aluminous earth, which will be precipitated by
the carbonate of potash, and without further investigation, would
be considered as so much calcareous earth. And if any compounds
of lime and vegetable acids are present (which, for reasons hereafter
to be stated, I believe to be not uncommon in soils), some portion
of these may be dissolved, and appear in the result as carbonate of
lime, though not an atom of that substance was in the soil. Thus,
every soil examined by this method of solution and .precipitation
will yield some small result of what would appear as carbonate of
lime, though actually destitute of that ingredient. ,The inaccura-
cies of this method were no doubt known (though passed over
without notice) by Davy, and other men of science who have
recommended its use; but as they considered calcareous earth
merely as one of the earthy ingredients of soil, operating me-
chanically (as do sand and clay), on the texture of the soil, they
would scarcely suppose that a diiFerence of a grain or two could
materially affect the practical value of an analysis, or the character
of the soil under examination.*

The pneumatic apparatus proposed by Davy, as another means
for showing the proportion of calcareous earth in soils, is liable to
none of these objections; and when some other causes of error,
peculiar to this method, are known and guarded against, its accu-
racy is almost perfect, in ascertaining the quantity of calcareous
earth — to which substance alone its use is limited.

* "Chalks, calcareous marls, or powdered limestone, act merely by form-
ing a useful earthy ingredicjit in the soil, aixd their efficacy is proportioned
to the deficiency of calcareous matter, which in larger or smaller quantities
seems to be an essential ingredient of all fertile soils ; necessary perhaps to
their proper texture, and as an ingredient in the organs of plants." [Da-
vy's Agr. Chem. page 21 — and further on he says] "Chalk and marl or
carbonate of lime only improve the texture of a soil, or its relation to absorp-
tion; it acts merely as one of its earthy ingredients." [It is evident, from these
expressions, that Davy considered calcareous earth important only as a
physical constituent of soils ; and it does not appear that he had any con-
ception of its far more important and useful service, in very minute pro-
portions, as a chemical agent, essential to fertilization,]

58

BY PNEUMATIC APPARATUS.

The following representation and description will make tlie ope-
ration quite clear :

" A, B, C, D, E, represent the different parts of this apparatus. A repre-
sents the bdttle for receiving the soil. B the bottle containing the acid,
furnished with a stop-cock. C the tube connected with a flaccid bladder.
D the graduated measure. E the bottle for containing the bladder. "When
this instrument is used, a given quantity of soil is introduced into A. B
is filled with muriatic acid diluted with an equal quantity of water ; and
the stop-cock being closed, is connected with the upper orifice of A, which
is ground to receive it. The tube C is introduced into the lower orifice of
A, and the bladder connected with it placed in its flaccid state into E,
which is filled with water. The graduated measure is placed under the
tube of E. AVhen the stop-cock of B is turned, the acid flows into A, anrl
acts flpon the soil ; the elastic fluid generated passes through C, into the
bladder, and displaces a quantity of water in E equal to it in bulk, and
this water flows through the tube into the graduated measure ; and gives
by its volume the indication of the proportion of carbonic acid disengaged
from the soil ; for every ounce measure of which two gi^ins of carbonate
of lime may be estimated." — Davy''s Agr. Chem.

The correctness of this mode of analysis depends on two well-
established facts in chemistry : 1st, That the component parts of
calcareous earth always hear the same proportion to each other, and
these proportions are as 43.7 parts (by weight) of carbonic acid, to
56.3 of lime ; and, 2d, That the carbonic acid gas which two grains
of calcareous earth will yield, is equal in bulk to one ounce of fresh
water. The process, with the aid of this apparatus, disengages,
confines, and measures the gas evolved ; and for every measure
equal to the bulk of an ounce of water, the operator has but to
allow two grains of calcareous earth in the soil acted on. It is
evident that the result can indicate the presence of lime in no other
combination except that which forms calcareous earth 3 nor of any

CALCAREOUS SOILS. 59

other earth, except carbonate of magnesia, which, if present, mfght
be mistaken for calcareous earth, but which is too rare, and occurs
in proportions too small, to cause any material error in ordinary
cases, and in soils of this region.

But if it be only desired to know whether calcareous earth is
entirely wanting in any soil — or to test the truth of my assertion
that so great a proportion of our soils are destitute of that earth
— it may be done with far more ease than by either of the forego-
ing methods, and without apparatus of any kind. Let a handful
of the soil (without drying* or weighing) be thrown into a large
drinking-glass, containing enough of pure water to cover the soil
about two inches. Stir it until all the lumps have disappeared,
and the water has certainly taken the place of all the atmospheric
air which the soil had enclosed. Bemove any vegetable fibres, or
froth, from the surface of the liquid, so as to have it clear. Then
pour in gently about a table spoonful of undiluted muriatic acid,
which by its greater weight will sink, and penetrate the soil, with-
out any agitation being necessary for that purpose. If any calca-
reous earth is present, it will quickly begin to combine with the
acid, throwing off its carbonic acid in gas, which cannot fail to be
observed as it escapes, as the gas that eight grains only of calca-
reous earth would throw out, would be equal in bulk to a gill
measure. Indeed, the product of a single grain only of calcareous
earth would be abundantly plain to the eye of the careful operator,
though it might be the whole amount of gas from two thousand
grains of soil. If no effervescence is seen even after adding more
acid and gently stirring the mixture, then it is absolutely certain
that the soil contained not the smallest portion of carbonate^ of
lime ] nor of carbonate of magnesia, the only other substance which
could possibly be mistaken for it.

The examinations of all the soils that will be here mentioned were
made in this pneumatic apparatus, except some of those which evi-
dently evolved no gas, and when no other result was required. As
calcareous earth is plainly visible to the eye in all shelly soils, they
only need examination to ascertain its proportion. A few examples
will show what proportions we may find, and how greatly they
vary, even in soils apparently of equal value.

1. Soil, a black clayey loam, from the top of the high knoll at
the end of Coggins Point [then my own farm], on James River, con-
taining fragments of mussel shells throughout. Never manured,
and supposed to have been under scourging cultivation and close
grazing from the first settlement of the country; then (1818) ca-
pable of producing twenty-five or thirty bushels of corn — and the
soil well suited to wheat. One thousand grains, cleared by a fine
sieve of all coarse shelly matter (as none can act on the soil until
minutely divided), yielded sixteen ounce measures of carbonic acid

60 CALCAREOUS SOILS.

gas, wliicli showed tlie finely divided calcareous earth to be thirty-
two grains.

2. One thousand grains of similar soil from another part of the
same field, treated in the^ame manner, gave twenty-four grains of
finely divided calcareous earth.

3. From the east end of a small island, at the end of Coggins
Point, surrounded by the river and tide marsh. Soil, dark brown
loam, much lighter than the preceding specimens, though not
sandy — under like exhausting cultivation — then capable of bring-
ing thirty to thirty-five bushels of ct^rn — not a good wheat soil,
ten or twelve bushels being probably a full crop. One thousand
grains yielded eight grains of coarse shelly matter, and eighty-two
of finely divided calcareous earth.

4: From a small spot of sandy soil, almost bare of vegetation,
and incapable of producing any grain, though in the midst of very
rich land, and cleared but a few years. Some small fragments of
fossil sea-shells being visible, proved this barren spot to be calca-
reous, which induced its examination. Four hundred grains yielded
eighty-seven of calcareous earth— nearly twenty-two per cent.
This super-calcareous soil was afterwards dug and carried out as
manure. [It is, in fact, the upper layer of a bed of fossil-shell
earth, the shells there being entirely disintegrated and invisible.]

5. Black friable loam, from Indian Fields, on York Iliver. The
soil was a specimen of a field of considerable extent, mixed through-
out with oyster shells. Though light and mellow, the soil did not
appear to be sandy. Eich, durable, and long under exhausting
cultivation.

1260 grains of soil yielded
168 — of coarse shelly matter, separated mechanically,
8 — finely divided calcareous earth.
The remaining solid matter, carefully separated (by agitation and
settling in water), consisted of
130 grains of fine clay, black with putrescent matter, and which
lost more than one-fourth of its weight by being ex-
posed to a red heat,
875 — white sand, moderately fine,
20 — very fine sand,
30 — lost in the process.

1061

6. Oyster shell soil, of the best quality, from the farm of Wills
Cowper, Esq., on Nansemond Iliver — never manured, and supposed
to have been cultivated in corn as often as three years in four, since
the first settlement of the country — now yields (by actual mea-
surement) thirty bushels of corn to the acre— but is very unproduc-

ALL POOR SOILS NOT CALCAREOUS. 61

tive in wheat. A specimen taken from the surface, to the depth
of six inches, weighed altogether
242 dwt., which consisted of

126 — of shells and their fragments, separated Iby the sieve,
116 — remaining finely divided soil.
Of the finely divided part, 500 grains consisted of

18 grains of carbonate of lime,
330 — silicious sand — ^none very coarse,

94 — impalpable aluminous and silicious earth,

35 — putrescent vegetable matter — none coarse or unrotted,

23 — loss.

500

It is unnecessary to cite any particular trials of our poor soils,
as it has been stated, in the preceding chapter, that all are entirely
destitute of calcareous earth — excluding the rare, but well marked
exceptions of its great excess, of which an example has been given
in the soil marked 4, in the foregoing examinations.

Unless then I am mistaken in supposing that these facts are
universally true, the certain results of chemical analysis, as well
as more extended general observation, completely establish these
general rules — viz. :

Xst. That all calcareous soils are naturally fertile and durable
in (Mvery high degree — and,

2d. That all soils naturally ^oor are entirely destitute of calca-
reous earth.

It then can scarcely be denied that calcareous earth must be the
cause of the fertility of the one class of soils, and that the want
of it produces the poverty of the other. Qualities that always
thus accompany each other cannot be otherwise than cause and effect.
If further proof is wanting, it can be safely promised to be fur-
nished when the practical application of calcareous manures to
poor soils will be treated of, and the efi"ects stated.

These deductions are then established as to all calcareous soils,
and all poor soils — which two classes comprise nine-tenths of all.
This alone would open a wide field for the practical exercise of the
truths we have reached. But still there remain strong objections
and stubborn facts opposed to the complete proof and universal
application of the proposition now under consideration, and conse-
quently to the theory which that proposition is intended to support.
The whole difficulty will be apparent at once when I now proceed
to state that nearly all of our best soils, such as are very little if
at all inferior in value to the small portion of shelly lands, are as
destitute of calcarjeous earth [carhonate of lime) as the poorest. So
far as I have examined, this deficiency is no less general in tho
6

62 MANY RICH SOILS NOT CALCAREOUS.

richest alluvial lands of tlie upper country — and, wliat will he
deemed by some as incredible, by far the greater part of the rich
limestone soils between the Blue Ridge and Alleghany IMountains
are equally destitute of •alcareous earth. These facts were not
named before, to avoid embarrassing the discussion of other points
— nor can they now be explained, and reconciled with my proposi-
tion, except through a circuitous and apparently digressive course
of reasoning. They have not been kept out of view, nor slurred
over, to weaken their force, and are now presented in all their
strength. These difficulties will be considered, and removed, in
the following chapters.

CHAPTER VI.

CHEMICAL EXAMINATION OP RICH SOILS CONTAINING NO CALCA-
REOUS EARTH,

Proposition 2 — continued.

Under common circumstances, when any disputant admits facts
that seem to contradiclr his own reasoning, such admission is
deemed abundant evidence of their existence. But though %ow
placed exactly in this situation, the facts admitted by me are so
opposed to all^ that scientific agriculturists have taught us to expect,
that it is necessary for me to show the grounds on which my ad-
mission rests. Few would have believed in the absence of calca-
reous earth in all our poor soils, forming as they do the much
larger part of all this region — and far more strange is it that the
same deficiency should extend to such rich soils as some that will
be here cited.

The following specimens, taken from well known and very fertile
soils, were found to contain no calcareous earth. Many trials of
other rich soils have yielded like results- — and, indeed, I have
never found calcareous earth in any soil below the falls of the
rivers, in which, or near which, some particles of shells were not
visible.

1. Soil from Eppes' Island, which lies in Powhatan, or James-
river, near City Point ; light and friable (but not sandy) brown
loam, rich and durable. The surface is not many feet above the
highest tides, and, like most of the best' river lands, this tract
seems to have been formed by alluvion many ages ago, but which
may be termed recent, when compared to the geaeral formation of
the tide-water district.

RICH RIVER AND LIME-STONE SOILS. 63

2. Black silicious loam from the celebrated lands on Back river,
near Hampton.

3. Soil from ricli land on Pocoson-river, York county.

4. Black clay vegetable soil, from a fre^-water tide marsh on
James river — formed by recent alluvion.

5. Alluvial soil of first-rate fertility above the falls of James
river — dark brown clay loam, from the valuable and extensive
body of bottom land belonging to General J. H. Cocke, of Flu-
vanna.

The most remarkable facts of the absence of calcareous earth
are to be found in the lime-stone soils, between the Blue Ridge
and Alleghany Mountains. Of these, I will report all that I have
examined ; and none contained any calcareous earth, unless when
the contrary will be stated.

Before the first of these trials was made, I supposed (as~ proba-
bly most other persons do) that limestone soil was necessarily
calcareous, and in a high degree. It is difficult to get rid of this
impression entirely — and it may seem a contradiction in terms to
say that a lime-stone soil is not calcareous. This I cannot avoid.
I must take the term limestone soil as custom has already fixed it.
But it should not be extended to any soils except those which are
so near to lime-stone rock, as in some measure to be thereby affected
in their qualities and value.

1 to 6. Lime-stone soils selected in the* neighbourhood of Lex-
ington, Virginia, by Professor Graham, with the view of enabling
me to investigate this subject. All the specimens were from first-
rate soils, except one, which was from land of inferior value. One
of the specimens, Mr. Graham's description stated to be ^' taken
from a piece of land so rocky [with lime-stone] as to be unfit for
cultivation, at least with the plough. I could scarcely select a
specimen which I would expect to be more strongly impregnated
with calcareous earth.'' This specimen, by two separate trials,
yielded only one grain of calcareous earth, from one thousand of
soil. The other five soils contained none. The same result was
obtained from

7. A specimen of gftuvial land on North river, near Lexington.

8. Brown loam from the Sweet Spring valley, remarkable for its
extraordinary productiveness and durability. It is of alluvial for-
mation, and before it was drained, must have been often covered
and saturated by the Sweet Spring and other mineral waters, which
hold lime in solution. [The carbonate of lime dissolved in these
waters is so abundant, and so readily parted "with, that it is depo-
sited on every twig that is exposed therein, forming rapidly grow-
ing incrustations.] The surrounding high land is of lime-stone
soil. Of this specimen, taken from about two hundred yards be-
low .the Sweet Spring, from land long cultivated every year, three

64 LIME-STONE SOILS.

hundred and sixty grains yielded not a particle of calcareous earth.
It contained an unusually large proportion of oxide of iron, though
my imperfect means enabled me to separate and collect only eight
grains, the process evidently wasting several more.

About a mile lower down, drains were then making (in 1826) to
reclaim more of this rich valley from the overflowing waters.
Another specimen was taken from the bottom of a ditch just
opened, eighteen inches below the surface. It was a black loam,
and exhibited to the eye some very diminutive fresh-water spiral
shells, about one-tenth of an inch in length, and many of their
broken fragments. This gave, from two hundred grains, seventy-four
of calcareous earth. But this cannot fairly be placed on the same
footing with the other soils, as it had obviously been once the bot-
tom of a stream, or lake, and the collection and deposit of so large
and unusual a proportion of calcareous matter seemed to be of ani-
mal formation. Both these specimens were selected at my request
by one of our best farmers, and who also furnished a written
description of the soils, and their situation. --

9. Wood-land, west of Union, Monroe county. Soil, a black
clay loam, lying on, but not intermixed at the surface with lime-
stone rock. Sub-soil, yellowish clay. The rock at this place, a
foot below the surface. Principal growth, sugar maple, white wal-
nut, and oak. This and the next specimen are from one of the
richest tracts of high latid that I have seen.

10. Soil similar to the last, and about two hundred yards distant.
Here the lime-stone showed above the surface, and the specimen
was taken from between two large masses of fixed rock, and about
a foot distant from each.

11. Black rich soil, from wood-land between the Hot and Warm
Springs, in Bath county. The specimen was part of what was in
contact with a mass of lime-stone.

12. Soil from the western foot of the Warm Spring mountain,
on a gentle slope between the court-house and the road, and about
one hundred and fifty yards from the Warm Bath. Rich brown
loam, containing many small pieces of lime-stone, but no finely
divided calcareous earth. 4&

13. A specimen taken two or three hundred yards from the last,
and also at the foot of the mountain. Soil, a rich black loam, full
of small fragments of lime-stone of different sizes, between that
of a nutmeg and small shot. The land had never been broken up
for cultivation. One thousand grains contained two hundred and
forty grains of small stone or gravel, mostly lime-stone, separated
mechanically, and sixty-nine grains of finely divided calcareous
earth.

14. Black loamy clay, from the excellent wheat soil adjoining
the town of Bedford, in Pennsylvania : the specimen taken from

LIME-STONE AND ALLUVIAL SOILS. " 65

beneath and in contact with lime-stone. One thousand grains
yielded less than one grain of calcareous earth.

15. A specimen from within a few yards of the last, but not in
contact with lime-stone, contained no calcareous earth ; neither did
the red clay sub-soil, six inches below the surface.

16. Very similar soil, but much deeper, adjoining the principal
street of Bedford — the specimen taken from eighteen inches below
the surface, and adjoining a mass of lime-stone. A very small
disengagement of gas indicated the presence of calcareous earth —
but certainly less than one grain in one thousand, and perhaps not
half that quantity.

17. Alluvial soil on the Juniata, adjoining Bedford.

18. Alluvial vegetable soil near the stream flowing from all the
Saratoga Mineral Springs, and necessarily often covered and soaked
by those waters, and

19. Soil taken from the bed of the same stream — ^neither con-
tained any portion of carbonate of lime.

Thus it appears that of these nineteen specimens of soils, only
four contained calcareous earth, and three of these four in exceed-
ingly small proportions. It should be remarked that all these
were selected from situations which, from their proximity to calca-
reous rock, or exposure to calcareous waters, were supposed most
likely to present highly calcareous soils. , If five hundred speci-
mens had been taken, without choice, even from what are commonly
called lime-stone soils (merely because they are not very distant
from lime-stone rock, or springs of lime-stone water), the analysis
of that whole number would be less likely to show calcareous
earth, than the foregoing short list. I therefore feel justified, from
my own few examinations, and unsupported by any other authority,
to pronounce that calcareous earth will very rarely be found in any
soils between the falls of our rivers and the navigable western
waters.* In a few specimens of some of the best soils from the
borders of the Mississippi and its tributary rivers, I have since \
found calcareous earth present in all — but in very small propor- l
tions, and in no case exceeding two per cent. '\

[When the total deficiency of carbonate of lime, in nearly all the \
soils of Virginia, was first asserted, as above, in the earliest publi- 1
cation of this essay (1821, in American Farmer^ vol. iii.), the |

[* Recent Confirmatory Testimony. — Still more strange cases of the total
absence of (carbonate of) lime have been stated recently in Johnston's
Agricultural Chemistry: " It is a fact which will strike you as not a little
remarkable that soils which rest upon chalk, as well as upon other
lime-stone rocks, even at the depth of a few inches only, are often, and
especially when in a state of. nature, so destitute of lime, that not a parti-
cle can be detected in them." (p. 377.) The author of course meant the
carbonate of lime. — 1819.]
6*

66 PRAIRIE SOILS CALCAREOUS.

proposition was so entirely new, and so opposed to all inferences
from authority then existing, that it was indispensably necessary to
adduce my facts, as is done above, to sustain the otherwise unsus-
tained doctrine. And such support, for the same reason, continued
to be wanting through the two next editions. Now (in 1842) the
case is altogether different. The fact of the absence of carbonate
of lime, as generally as I had assumed, through the eastern or
seaward slope of the United States, and especially in New England,
has been confirmed by all the analyses of soils which have been
since made by Professor Hitchcock and other accurate scientific
investigators ', and the proposition, however untenable or incredible
it might have been deemed before, is now universally admitted, and
indeed is placed beyond question or doubt, as an important feature
in 4he chemical constitution of soils. — 1842.]

[The only soils of considerable extent of surface which, from the
specimens that I have examined, appear to be highly calcareous,
and to agree in that respect with many European soils, are from
the prairies, those lands of the south-west which, whether rich or
poor, are remarkable for being destitute of trees, and covered with
grass, so as to form natural meadows. The examinations were
made but recently (in 1834), and are reported because presenting
striking exceptions to the general constitution of soils in this
country.

20. Prairie soil of the most productive kind in /Alabama ; a
black clay, with very little sand, yet so far from being stiff, that it
becomes too light by cultivation. This kind of land is stated by
the friend to whom I am indebted for the specimens, to ^^ produce
corn and oats most luxuriantly — and also cotton for two or three
years ; but after that time cotton is subject to the rust, probably
from the then open state of the soil, which by cultivation has by
that time become as light and as soft as a bank of ashes.'' One
hundred grains of the specimen contained eight of carbonate of
lime. All this prairie land in Alabama lies on a substratum of
what is there called "rotten lime-stone" (specimens of which con-
tained seventy-two to eighty-two per cent, of lime), and which
rises to the surface sometimes, forming the "bald prairies,'' a sam-
ple of the soil of which (21) contained fifty-nine per cent, of car-
bonate of lime. This was described as " comparatively poor —
neither trees nor bushes grow there, and only grass and weeds be-
fore cultivation — corn does not grow well — small grain better —
and cotton soon becomes subject to the rust." The excessive pro-
portion of calcareous earth is evidently the cause of its barrenness.
The substratum called lime-stone is soft enough to be cut easily
and smoothly with a knife, and some of it is in appearance and
texture more like the chalk of Europe, than any other earth that
I have seen in this country.

^ PRAIRIE SOILS. 67

22. A spedmen of the very rich ^^ cane brake" lands in Marengo
county, Alabama, contained sixteen per cent, of carbonate of lime.
This is a kind of prairie, of a wetter nature, from the winter rains
not being able to run off from the levd surface, nor to sink through
the tenacious clay soil, and the solid stratum of lime-stone below.

23. A specimen from the very extensive "Choclaw Prairie" in
Mississippi, of celebrated fertility, yielded thirteen per cent, of
carbonate of lime.

Several other specimens of different, but all of very fertile soils
from southern Alabama, and all lying over the substratum of soft
lime-stone, were found to be neutral, containing not a particle of
lime in the form of carhonate. These specimens were as follows :

24. One from the valley cane land— ^' very wet through the
winter, but always dry in summer — and after being ditched is dry
enough to be cultivated in cotton, which will grow from eight to
twelve feet high."

25. Another from what is called the best ^^ post-oak land," on
which trees of that kind grow to the size of from two to four feet
in diameter — having but little underwood, and no cane growth —
*' thought to be nearly as rich as the best cane laud, and will pro-
duce 1500 lbs., or more, of seed cotton, or fifty bushels of corn to
the acre."

26. Another from what is termed " palmetto land, having on it
that plant as well as a heavy cover of large trees growing luxuri-
antly. It is a cold and wet soil before being brought into good
tilth ; but afterwards is soft and easy to till, and produces corn and
cotton finely. The cane on it is generally small — the soil from
four to ten feet deep."

One more prairie soil only will be adduced, from many analyses
which have furnished general results like the foregoing (20 to 26) ;
and this one is given because it serves as a fair specimen of a very-
large class of the prairie lands. It was selected by Dr. R. W.
Withers, in 1835, and described by him as follows : {Farmer^
Register, vol. iii. p. 498.)

27. Soil of Gceene county, Alabama, ^^ from our open or hald
prairie, \_i. e., totally without trees,] which has been cultivated for
seven or eight years — produces corn very well — nearly fifty bushels to
the acre are now standing on the ground ; but cotton does not pro-
duce so well on it as on poor sandy soil. I feel very confident that
this specimen is highly calcareous, as there are many fragments of
shells mixed with the soil, and the rock is not two feet from the
surface. Of all the specimens hitherto sent, this is the one which
will give the nearest approach to the general character of our open
prairie land in this part of the country." — This specimen was
found to contain 33 per cent, of carbonate of lime. — 1835.]

The foregoing details, respecting lime-stone lands, may perhaps

6d LIME ESSENTIAL TO FERTILE SOIL.

be considered an unnecessary digression, in a treatise on the soils
of the tide-water district. But the analysis of lime-stone soils
furnishes the strongest evidence of the remarkable and novel fact
of the general absence of calcareous earth — and the information
thence derived will be used to sustain the following steps of my
argument.

All the examinations of soils in this chapter concur in opposing
the general application of the proposition that the deficiency of
calcareous earth is the cause of the sterility of our soils. And
having stated the objection in all its force, I shall now proceed to
inquire into its causes, and endeavour to dispel its apparent opposi-
tion to my doctrine.

CHAPTER VII.

PROOFS OF THE EXISTENCE OF ACID AND NEUTRAL SOILS.

Proposition 2 — continued.

Sufficient evidence has been adduced to prove that many of our
most fertile and valuable soils are destitute of calcareous earth.
But it does not necessarily follow that such has always been their
composition ; or that they may not now contain enough lime com-
bined with some other acid than the carbonic. That this is really
the case, I shall now offer proofs to establish; and not only main-
tain this position with regard to those valuable soils, but shall con-
tend, that lime, in some proportion, combined with vegetable acidy
is present in every soil capable of supporting vegetation.

But, while I shall endeavour to maintain these positions, without
asking or even admitting any exception, let me not be understood
as asserting that the degree of natural fertility of a calcareous soil
is in proportion to the amount of calcareous earth contained ; or,
that the knowledge of the proportion of calcareous earth, or of lime
in any form, contained, would serve to measure the capacity of the
soil for production or for fertilization. On the contrary, chalky
and calcareous soils, not differing materially in agricultural qualities
or fertility, sometimes exhibit remarkable differences in their pro-
portions of calcareous earth ; so that one soil, having less than one
per cent., may seem as well constituted and as valuable as another
having ten per cent,, or more. [The reason is, that a very small
proportion is enough for the full chemical action ; and that any
surplus, even if not hurtful by its amount, will have no other than
the comparatively feeble mechanical action — which may even be
injurious, and in opposition to, and counteracted by the chemical
action.]

.ACID AND NEUTRAL SOILS DEFINED. Q9^

Tn all naturally poor soils, producing freely pine and wliortle-
berry in their virgin state, and sheep-sorrel after cultivation, I sup-
pose to have been formed some vegetable acid, which, after taking
up, audi combining with whatever small quantity of lime might
have been present, still remains in excess in the soil, and nourishes
in the highest degree the plants named above, but is a poison to all
useful crops; and effectually prevents such acid soils from becom-
ing rich, by either natural or artificial applications of putrescent
manures.

In a neutral soil, I suppose calcareous earth to have been suffi-
ciently abundant at some former time to induce a high degree of
fertility — but that it has been decomposed, and the lime taken up,
by the gradual formation of vegetable acid, until the lime and the
acid neutralize and balance each other, leaving no considerable ex-
cess of either; and thalPsuch are all our fertile soils which are not
now calcareous.

Both these suppositions remain to be proved, in all their parts.

No opinion has been yet advanced that is less supported by good
authority, or to which more general opposition may be expected, than
that which supposes the existence of acid soils. The term sour soil
is indeed frequently used by farmers, but in so loose a manner as
to deserve no consideration. It has been thus applied to any moist,
cold, and ungrateful land, without intending that the term should
be literally understood, and perhaps without attaching to its use
any precise meaning whatever. Dundonald only, of all those
who have applied chemistry to agriculture, has asserted the exist-
ence of vegetable acid in soils :* but he has offered no analysis
of soils in proof, nor any other evidence to establish the fact ; and
his opinion has received no confirmation, nor even the slightest no-
tice, from later and more able investigators of the chemical cha-
racters of soils. Kirwan and Davy profess to enumerate all the
common ingredients of soils; and it is not intimated by either
tliat vegetable acid is one of them. Even this tacit denial by
Davy more strongly opposes the existence of vegetable acid, than it
is supported by the opinion of Dundonald, or any early writers on
agriculture, if there be any who may have admitted' its existence.
[For it cannot be supposed that so able and profound an investiga-
tor would have omitted all reference to an ingredient of soils so
general, and therefore so important, as is here asserted, even if its
presence had been even suspected by him, much less if fully known.]
Grisenthwaite, a late writer on agricultural chemistry, and who has
the advantage of knowing the discoveries, and comparing the
opinions, of all his predecessors, expressly denies the possibility of
any acid existing in soils. His Meio ^Theory of Agriculture' ■\ con-

* Dundonald's Connexion of Chemistry and Agriculture,
f Republished in American Farmer, (old) vol. ii.

70 CHEMICAL AUTHORITY OPPOSED TO ACID^OIL.

tains tliG following passage : '' Chalk has been recommended as a
substance calculated to correct the sourness of land. It would
surely have been a wise practice to have previously ascertained this
existence of acid, and to have determined its nature, in order that
it might be effectually removed. The fact really is, that no soil
was ever yet found to contain any notable quantity of acid. The
acetic and the carbonic are the only two that are likely to be gene-
rated by any spontaneous decomposition of animal or vegetable
bodies, and neither of them have any fixity when exposed to the
air.'' Thus, then, my doctrine is deprived of even the feeble sup-
port it might have had from Dundonald's mere opinion, if that
opinion had not been contradicted by later and better authority ;
and the only support to be looked for, will be in the facts and argu-
ments that I shall be able to adduce.

I am not prepared to question what Glisenthwaite states as a
chemical fact, ^'ihut no soil was ever yet found to contain any
notable quantity of acid.'' No soil examined by me for this pur-
pose, with sufh poor means as I could apply, gave any evidence of
the presence of uncombined acid. Still, however, the term acid
may be applied with propriety to soils in which growing vegetables
continually receive acid from the decomposition of others (for which
no " fixity" is requisite), or in which acid is present, not free, but
combined with some base, by which it is readily yielded, to promote,
or retard, the growth of plants in contact with it. It will be suffi-
cient for my purpose to show that certain soils contain some sub-
stance, or possess some quality, which promotes almost exclusively
the growth of acid plants — that this power is strengthened by
adding known vegetable acids to the soil — and is totally removed
by the application of calcareous manures, which would necessarily
destroy any acid, if it were present. Leaving it to chemists to
determine the nature and properties of this substance, I merely
contend for its existence and efiects; and the cause of these effects,
whatever it may be, for the want of a better name, I shall call
aciditT/.

The proofs now to be offered in support of the existence of acid
and neutral soils, however weak each may be when considered alone,
yet, when taken in connexion, will together form a body of evidence
not easily to be resisted.

First proof. — Pines and common sorrel [rumex acetocella] have
leaves well known to be acid to the taste ; and their growth is fa-
voured by such soils as are here supposed to be acid, to an extent
which would be thought remarkable in other plants on the richest
soils. Except wild locust on the best of our.river land, no growth
can compare in rapidity with pines on soils naturally poor, and
even when greatly reduced by long cultivation. Pines usually
stand so thick; on old exhausted fields, that the increase of size in

PROOFS OP ACID SOILS. 71

each plant is greatly retarded ; but if the whole growth of an acre
were estimated, it would probably exceed in quantity the different
growth of the richest soils, of the same age and on an equal space.
Every cultivator of corn on poor light soil knows how rapidly
sorrel"^ will cover his otherwise naked field, unless kept in check by
continual tillage — and that to root it out, so as to prevent the like
future labour, cannot be effected by any mode of cultivation what-
ever. This weed too is considered far more hurtful to growing
crops, than any other of equal size. Yet neither of these acid
plants can thrive on the best lands. Sorrel cannot even' live on a
calcareous soil; and if a pine is sometimes found there, it has
nothing of its usual elegant form, but seems as stunted and ill-
shaped as if it had always suffered for want of nourishment. In-
numerable facts, of which these are examples, prove that these acid
plants must derive from their favourite soil some kind of food pe-
culiarly suited to their growth, and quite useless, if not hurtful, to
cultivated crops.

2d. Dead acid plants are the most effectual in promoting the
growth of living ones. When pine leaves are applied to a soil,
whatever acid they contain is of course given to that soil, for such
time as circumstances permit it to retain its form, or peculiar pro-
perties. Such an application is often made on a'large scale, by
cutting down the second growth of pines, on land once under till-
age, and suffering them to lie a year before clearing and cultivating
the land. The invariable consequence of this course is a growth
of sorrel, for one or two years, so abundant and so injurious to the
crops, as to more than balance any benefit derived by the soil from
the vegetable matter having been allowed to rot. From the gene-
ral experience of this effect, most persons put pine land under
tillage as soon as cut down, after carefully burning (to destroy) the
whole of the heavy cover of leaves, both green and dry. Until
within a few years, it was generally supposed that the leaves of
pine were worthless, if not hurtful, in all applications to cultivated
lapd — which opinion doubtless was founded on such facts as have
been just stated. But if they are used as litter for cattle, and
heaped to ferment, the injurious quality of pine leaves is destroyed,
and they become a valuable manure. This practice is but of recent
origin — but is highly approved, and rapidly extending. [Still
later it has been found that when these leaves are applied unrotted,
as raked up in woodland, to calcareous land, they produce only and

* Sheep sorrel, or Rumez acetocella. The wood sorrel {Oxalis acetocella)
is of a very different character. The latter prefers rich and even calcareous
Boils, and I have seen it growing well on spots calcareous to excess. It
would seem, therefore, that wood sorrel forms its acid from the atmosphere,
and does not draw it from the soil, as I suppose to be the case with common
sorrel. [The wood sorrel is a trefoil, and pod-bearing or leguminous
plant.]

72 PROOFS OF ACID SOILS.

always benpficial results ; and that this is the best as well as cheap-
est mode of their application.]

On one of the washed and barren declivities (or galli) which are
so numerous on all our farms, I had the small gullies packed full
of green pine bushes, and then covered with the earth drawn from
the equally barren intervening ridges, so as nearly to smooth the
whole surface. The whole piece had borne nothing previously ex-
cept a few scattered tufts of poverty grass (aristlda (jracilis) and
dwarfish sorrel, all of which did not prevent the spot seeming quite
bare at mid-summer, if viewed at some distance. This operation
was performed in February or March. The land was not culti-
vated, nor again observed, until the second summer afterwards. At
that time, the piece remained as bare as formerly, except along the
filled gullies, which, throughout the whole of their crooked courses,
were covered by a thick and uncommonly tall growth of sorrel, re-
markably luxuriant for any situation, and which, being bounded
exactly by the width of the narrow gullies, had the appearance of
some vegetable sown thickly in drills, and kept clean by tillage.
So great an effect of this kind has not been produced within my
knowledge — though facts of like nature, and leading to the same
conclusion, are of frequent occurrence. If small pines standing
thinly over a broom-grass old-field are cut down and left to lie, un-
der every top will be found a patch of sorrel, before the leaves have
all rotted.

3d. The growth of sorrel is not only peculiarly favoured by the
application of vegetables containing acids already formed, but also
by such matters as will form acid in the course of their decomposi-
tion. Farm-yard manure, and all other putrescent animal and
vegetable substances, form acetic acid as their decomposition pro-
ceeds.'*' If heaps of rotting manure are left without being spread,
in a field but very slightly subject to produce sorrel, a few weeks
of growing weather will bring out that plant close around every
heap ; and for some time the sorrel will continue to show more
benefit from that rank manuring than any other grass. For several
years my winter-made manure was spread and ploughed in on land
not cultivated until the next autumn, or the spring after. This
practice was founded on the mistaken opinion, that it would prevent
much of the usual exposure to evaporation and waste of the manure.
One of the reasons which alone would have compelled me to aban-
don this absurd practice was, that a crop of sorrel always followed,
(even on neutral or good soils that before barely permitted a scanty
growth of it to live), which so injured the next grain crop as
greatly to lessen the benefit from the manure. Sorrel unnaturally
produced by such applications does not infest the land longer than

* Agr. Chem. p. 187. (PMl. ed.)

PROOFS OF ACID SOILS. 73

until we may suppose the recent supply of acid to Lave been re-
moved by cultivation and other causes.

It may be objected that, even if fully admitted, my authorities
prove only the formation of a single vegetable acid in soil, the acetio
— that my facts show only the production of a single acid plant,
sorrel — and that the acid which sorrel contains is not the acetic,
but the oxalic* In reply to such objections, it may be said, that
from the application of acids to recently ploughed land, no acid
plant except sorrel is made to grow, because that one only can
spring up speedily enough to arrest the the fleeting nutriment. Po-
verty grass (Aristida gracilis or A. dichofoma) grows only on the
same kinds of soil, and generally covers them after they have been
a year free from a crop, but does not show sooner ; and pines re-
quire two years before their seeds will produce plants. But when
pines begin to spread over the land, they soon put an end to the
growth of all other plants, and are abundantly supplied with their
acid food, from the dropping of their own leaves. Thus they may
be first supplied with the vegetable acid ready formed in the
leaves, and afterwards with the acetic acid, formed by their sub-
sequent slow decomposition. It does not weaken my argument,
that the product of a plant is a vegetable acid different from the
one supposed to have nourished its growth. All vegetable acids
(except the prussic), however different in their properties, are com-
posed of the same three elementary bodies, differing only in their
proportions^ — and consequently are, all convertible into each other.
A little more, or a little less of one or the other of these ingre-
dients, may change the acetic to the oxalic acid, and that to any
other. We cannot doubt but that such simple changes may be
produced by the chemical powers of vegetation, when others are
effected far more difficult for us to comprehend. The most tender
and feeble organs, and the mildest juices, aided by the power of
animal or vegetable life, are able to produce decompositions and
combinations which the chemist cannot explain, and which he would
in vain attempt to imitate.

4th. This ingredient of soils, which nourishes acid plants, also
poisons cultivated crops. Plants have not the power of rejecting
noxious fluids, but take up by their roots everything presented in a
soluble form-i Thus the acid also enters the sap-vessels of culti-
vated plants, stints their growth, and makes it impossible for them
to attain that size and perfection which their proper food would
insure, if it were presented to them without its poisonous accom-
paniment. When the poorest virgin wood-land is cut down, it is

^ Agr. Chem. Lecture 3.

f Carbon, oxygen, and hydrogen, Agr. Chem. Lecture 8, p. 78.

j Agr. Chem. Lecture C, page 186.

7

74 PROOFS OP NEUTRAL AND ACID SOILS,

covered and filled to excess with leaves and other rotted and rotting
vegetable matters. Can a heavier vegetable manuring be desired?
And as this completely rots during cultivation, must it not oiFer to
the growing plants as abundant a supply of food as they can re-
quire ? Yet the best product obtained may be from ten io fifteen
bushels of corn, or five or six of wheat, soon to come down to half
those quantities. If the noxious quality which causes such injury
is an acid, it is as certain as any chemical truth whatever,, that it
will be neutralized, and its powers destroyed, by applying enough
of calcareous earth to the soil ; and precisely such effects are found
wherever that remedy is tried. On land thus relieved of this un-
ceasing auTioyance, the young plants of corn no longer appear of a
pale and sickly green, approaching to yellow, but take immediately
a deep healthy colour, by which they may readily be distinguished
from any on adjoining ground, left in its former state, before there
is any perceptible difference in the size of the plants. The crop
will produce fifty to one hundred per cent, more, the first year, be-
fore its supply of food can possibly have been increased; and the
/ soil is soon found not only clear of sorrel, but absolutely incapable
of producing it. I have anticipated these effects of calcareous ma-
nures, before furnishing the evidence ; but they will hereafter be
established by facts beyond contradiction.

The truth of the existence of either acid or neutral soils depends
on the existence of the other ; and to prove either, will necessarily
establish both. If acid exists in soils, then whenever it meets with
calcareous earth, the two substances must combine with and neu-
tralize each other, so far as their proportions are properly adjusted.
On the other hand, if I can show that compounds of lime and vege-
table acid are present in most soils, it follows inevitably that nature
has provided means by which soils can generally obtain this acid ;
and if the amount formed can balance the lime, the operation of
the same causes can exceed that quantity, and leave an excess of
free acid. From these premises will be deduced the following
proofs.

5th. It has been stated (page 57) that the process recommended
by chemists for finding the calcareous earth in soils was unfit for
that purpose, because some precipitate was always obtained, even
when no calcareous earth or carbonate of lime was present. Fre-
quent trials have shown me that this precipitate is considerably
more abundant from good soils than bad. The substance thus ob-
tained from rich soils by solution and precipitation, in every case
that I have tried, contains some carbonate of lime, although the
soil from which it was derived had none. The alkaline liquor from
which the precipitate has been separated, we are told by Davy, will,
after boiling, let fall the carbonate of magnesia, if any had been in
the soil ; but when any notable deposit is thus obtained;^ it will

DISAPPEARANCE OF CARBONATE OF LIME IN SOILS. 75

often be found to consist more of carbonate of lime, than of mag-
nesia. The following are examples of such products :

One thousand grains of tide-marsh soil (page 63, No. 4), acted
on by muriatic acid in the pneumatic apparatus, gave out no car-
bonic acid gas, and therefore could have contained no carbonate of
lime. The precipitate obtained from the same weighed sixteen
grains ; which being again acted on by sulphuric acid, evolved as
much gas as showed that three grains had become carbonate of
lime, in the previous part of the process.

Two hundred grains of alluvial soil from Saratoga Springs (page
65, No. 18), containing no carbonate of lime, yielded a precipitate
of twelve grains, of which three was carbonate of lime — and a
deposit from the alkaline solution weighing six grains, four of
which was carbonate of lime.

Seven hundred grains of limestone soil from Bedford, Pennsyl-
vania (part of the specimen marked 14, page 64), contained about
two-thirds of a grain of carbonate lime — and its precipitate of
twenty-eight grains, only yielded two grains : but the alkaline
solution deposited eleven grains of the carbonates of lime and
magnesia, of which at least five was of the former, as there
remained seven and a half of solid matter, after the action of sul-
phuric acid.*

[Eleven hundred and fifty grains of the rich alluvial earth depo-
sited by the Mississippi river, in Arkansas, yielded, in the pneu-
matic apparatus, 9^ ounce measures of carbonic acid gas, and
of course could not have contained more than nineteen grains of
carbonate of lime, — or, so far as the carbonate was of magnesia,
something less in proportion. But by adding carbonate of potash
to the acid solution, fifty-two grains were precipitated, all of which,
according to Davy, should have been carbonate of lime ', and from
the alkaline solution thus made, by standing and boiling, 20 ^
grains more of solid matter was precipitated, which, according to
Davy, should have been carbonate of magnesia ; and making of

■^ The measurement of the carbonic acid gas evolved was relied on to
show the whole amount of carbonates present — and sulphuric acid was used
to distinguish between lime and magnesia, in the deposit from the alkaline
solution. If any alumina or magnesia had made part of the solid matter
exposed to diluted sulphuric acid, the combinations formed would have
been soluble salts, which would of course have remained dissolved and in-
visible in the fluid. Lime only, of the four chemical earths, forms with
sulphuric acid a substance but slightly soluble, and which therefore can be
mostly separated in a solid fonn. The whole of this substance (sulphate
of lime) cannot be obtained in this manner, as a part is always dissolved ;
but Avhatever is obtained, proves that at least two-thirds of that quantity
of carbonate of lime had been present ; as that quantity of lime which will
combine with enough carbonic acid to make 100 parts (by weight) of car-
bonate of lime, will combine with so much more of sulphuric acid, as to form
about 150 parts of the sulphate of lime, or gypsum.

76 • NEUTRAL SOILS.

both precipitates (52 + 20 j^) 72-2-. grains of carbonates of lime
and magnesia, for the quantity in the original specimen of soil.
Yet the first operation clearly proved there could have been no more
than nineteen. Subsequent information and experience showed
that Davy's mode for separating the results of lime and magnesia
was as little to be relied on, as that for ascertaining the quantity
of carbonate of lime alone.]

From these processes, there can be no doubt but that the soils con-
tained a proportion of some salt of lime (or lime combined with some
kind of acid), which being decomposed by and combined with the
muriatic acid, was then precipitated, not in its first form, but in
that of carbonate of lime — it being supplied with carbonic acid
from the carbonate of potash used to produce the precipitation.
The proportions obtained in these cases were small ; but it does not
follow that the whole quantity of lime contained in the soil was
found. However, to the extent of this small proportion of lime, is
proved clearly the presence of enough of some acid (and that not
the carbonic) to combine with it. Neither could it have been the
sulphuric, or the phosphoric acid ; for though both the sulphate and
phosphate of lime are in some soils, yet neither of these salts can
be decomposed by muriatic acid.

Qth. The strongest objection to the doctrine of neutral soils is,
that, if true, the salt formed by the combination of the lime and
acid must often be present in such considerable proportions, that it
is scarcely credible that its presence and nature should not have
been discovered by any of the able chemists who have analyzed
soils.* This difficulty I cannot remove, but it may be met (or

* This difficulty, founded on my then profound and often misplaced re-
spect for all scientific authorities, would have been less, if my own acquaint-
ance with chemistry and chemists had been greater. Boussingault says
that any substance in minute quantity, not appearing among the results of
analyses by chemists, is by no means evidence that such substances might
not have been present, and even easily detected in the original body ana-
lyzed. Thus, he adds, "iodine and bromine for a long time escaped notice
in all the analyses of sea-water. Chemists, in fact, only discover readily
the bodies which exist in some very appreciable quantities in the com-
pounds they examine. The substances whose presence is not foreseen,
those which only enter in extremely small quantity in a mineral, are apt to
pass the eyes unperceived, of even the most skilful and conscientious."
Rur. Econ. ^c, p. 205.

Stephens, in his late "Book of the Farm," in reference to his reports
of analyses of soils, says: " I regret that I must refer to foreign works to
furnish these analyses ; but the truth is, we have not one single published
analysis of British soil by a British chemist which is worth reading. Sir
Humphry Davy just analyzed soil to determine the amount of the first four
substances mentioned [silica, alumina, oxide of iron, and oxide of man-
ganese], and one or two others, and failed to detect five or six of the most
important ingredients." (P. 224, of republication in Skinner's Farmer's
Library.) •

NEUTRAL SOILS. 77

neutralized, to borrow a figure from my subject) j by sliowing that
an equal difficulty awaits those who may support the other side of
the argument.

The theory of geologists of the formation of soils, from the de-
composition or disintegration of rocks, is received as true by all
scientific agriculturists. The soils thus supposed to be formed, re-
ceive admixtures from each other, by means of difi'erent operations
of nature, and after being more or less enriched by the decay of
their own vegetable products, make the endless variety of existing
soils.* But where a soil, lying on and thus supposed to have been
formed from any particular kind of rock, is so situated that it could
not have been moved, nor received considerable accessions from
torrents or other agents, then, according to this theory, the rock
and the soil should be composed of the same materials ; aud such
soils as the specimens, marked 11 and 16 (page 64), would be, like
the rock they touched, nearly pure calcareous earth, instead of be-
ing (as they were in truth) destitute, or nearly so, of that ingre-
dient. Such are the doctrines received and taught by Davy, or the
unavoidable deductions from them. But, without contending for
the full extent of this theory of the formation of soils, every one
must ddmit that soils thus situated must have received, in the lapse
of ages, some accessions to their bulk, from the eff"ects of frost,
rain, sun, and air, on the lime-stone in contact with them. All
lime-stone soils, properly so called, exhibit certain marked and pe-
culiar characters of colour, texture, and products, which can only
be derived from receiving into their composition more or less of the
rock which lies beneath, or rises above their surface. This mixture
will not be denied by any one who has observed lime-stone soils,
and reasons fairly, whether his investigation begins with the causes,
or their efi'ects. If then all this accession of carbonate of lime re-
mains in the soil, why is it that none, or almost none, is discovered
by accurate chemical analysis ? Or, if it be supposed not present,
nor yet changed in its chemical character, in what possible manner
could a ponderous and insoluble earth have made its escape from
the soil ? To remove this obstacle, without admitting the opera-
tion of acid in making such soils neutral, will be attended with at
least as much difficulty, as any arising from that admission being made.

Itli. But we are not left entirely to conjecture that soils were
once more calcareous than they now are, if chemical tests can be
relied on to furnish proof. Acid soils that have received large
quantities of calcareous earth as manure, after some time, will yield
very little when analyzed. To a soil of this kind, full of vegetable
matter, I applied, in 1818 and 1821, fossil shells at such a known

* Agr. Chem. p. 131. Also Treatise on Agriculture (by General Arm-
Btrong), quoted in a preceding page (53) of this essay.
7*

78 DISAPPEARANCE OF CARBONATE OF LIME IN SOIL.

and heavy rate as would Lave given to the soil (by calculation) at
least three per cent, of calcareous earth, for the depth of five
inches. Only a small portion of the shelly matter was very finely
divided when applied. Since the application of the greater part
of this dressing (only one-fourth having been laid on in 1818), no
more than six years had passed before the following examinations
were made (at end of 1826) ; and the cultivation of five crops in
that time, three of which were horse-hoed, must have well mixed
the calcareous earth with the soil. Three careful examinations
gave the following results :

No. 1. — 100 grains yielded 7 J of coarse calcareous earth (fragments
of shells),

And less than i of finely divided.

8

No. 2. — 1000 grains yielded 5 of coarse,

2 finely divided,

7

No. 3. — 1500 grains yielded 15 of coarse,

2i finely divided.

17^

The specimens. No. 1 and No. 2, were obtained by taking hand-
fuls of soil from several places (four in one case, and twelve in the
other), mixing them well together, and then taking the samples
for trial from the two parcels. On such land, when not recently
ploughed, there will always be an over-proportion of the pieces of
shells on the surface, as the rains have settled the fine soil, and
left exposed the coarser matters. On this account, in making
these two selections, the upper half-inch was first thrown aside, and
the handful dug from below. No. 3 was taken from a spot show-
ing a full average quantity of small fragments of shells, and in-
cluded the surface. I considered the three trials made as fairly as
possible, to give a general average. Small as is the proportion of
finely divided calcareous earth exhibited, it must have been in-
creased by rubbing some particles from the coarser fragments, in
the operation of separating them by a fine sieve. Indeed it may
be doubted whether any proportion remained very finely divided —
or in other words, whether it had not been combined with acid, as
fast as it was so reduced. But without the benefit of this supposi-
tion, the finely divided calcareous earth in the three specimens
averaged only one ^nd one-fourth grains to the thousand, which is
one twenty-fourth of the quantity laid on; and the total quantity

DISAPPEARAN-CE OP CARBONATE OF LI^IE FROM SOIL. 79

olDtained, of coarse and fine, is eight grains in one thousand, or
about one-fourth of the original proportion. All the remainder
had changed its form, or otherwise disappeared, in the few years
that had passed since the application.*

^Another similar trial of this soil from the same ground was re-
peated in July, 1842, which showed that the finely divided carbo-
nate of lime, then remaining, was in quantity so small as to be
barely perceptible and appreciate. The land had then remained
undisturbed by tillage for nine months j and some scattered frag-
ments of shells were exposed to view on the surface generally.
For the obvious reasons stated in the preceding paragraph, there
will always appear an over-proportion of such fragments, upon the
surface of land not recently ploughed ; for this reason, as on two
of the three former trials, the upper half-inch of surface soil was
thrown aside, andd the sample for examination taken immediately
below. Of this, 2400 grains yielded two grains only of small
fragments of shells, and less than one grain of finely divided car-
bonate of lime ; whereas seventy-two grains had been the original
quantity furnished to the soil. This result, with those of the
earlier trials, agree precisely with what would be expected from the
action of acid in soil, and cannot be satisfactorily explained by
any other doctrine.f — 1842.]

[* An experiment conducted by Lampadius, and quoted by Johnston in
his recent work, is very like the above, and shows like results. " He
mingled [the carbonate of] lime with the soil of a piece of ground till it
was in the proportion of 1.19 per cent of the whole, and he determined
subsequently by analysis, the quantity of lime it contained in each of the
three succeeding years.

1st year it contained 1.19 per cent, of carbonate of lime.

2d year . . 0.89 « "

3d year . . 0.52 " «

4th year . . 0.24 " "

But from these premises, so similar to mine, it must be admitted that
Prof. Johnston arrives at a very different conclusion. lie takes the gradual
lessening of the carbonate as proving the entire removal from the soil of so
much lijne; while I considered it as showing merely the change from the
carbonate to some other salts of lime. — 1840.]

[f Even of this very small amount of fragments of shells found (2 grains),
more than half was of the very hard gray shells (oyster and scallop),
which seem almost indestructible in soil. They must contain some chemi-
cal ingredient which enables them to withstand the acid or other corroding
action of soil, to which all the white fossil shefis, whether hard or soft, so
readily yield in the course of time. I recently observed a most striking
proof of this well known general fact of the long durability of these gray
shells, and consequently their comparative worthlessness as a manure. On
like soil to the su])ject of the above trials, and near the same spot, I
recently (1842) found a small and thin but well-marked oyster-shell (Ostrea
Virginiana), apparently as perfect and as well preserved as when it was
dug up, and which was a good characteristic specimen of the kind, and, as

80 PROOFS or NEUTRAL SOILS.

The very small proportions of finely divided calcareous earth
compared to the coarse, in some shelly soils, furnish still stronger
evidence of this kind. Of the York river soil (described page 60
No. 5), ^ ^

1260 grains, yielded of coarse calcareous parts, - 168 grains.
And of finely divided, _ - - - 8

1044 of the rich Nansemond soil TNo. 6), - - 544 coarse:

- 18 fine.

As many of the shells and their fragments in these soils are in a
mouldering state, it is incredible that the whole quantity of finely
divided particles derived from them should have amounted to no
more than these small proportions. Independent of the action of
natural causes, the plough alone, in a few years, B»ust have pulver-
ized at least as much of the shells as was found.

8th. In other case.s, where the operations of nature have been
applying calcareous earth for ages, none now remains in the soil ;
and the proof thence derived is more striking than any obtained
from artificial applications of only a few years' standing. Valleys,
Bubject to be frequently flooded and saturated by the water of lime-
stone streams, must necessarily retain a new supply of calcareous
earth from every such soaking and drying. Lime-stone water con-
tains the super-carhonatc of limey which is soluble ; but this loses
its excess of carbonic acid when left dry by evaporation, and be-
comes the carbonate of lime, which not being soluble, is in no
danger of being removed by subsequent floods. Thus, accessions
are slowly but continually made, through many centuries. Yet
such soils are found containing no calcareous earth — of which a
remarkable example is presented in the soil of the cultivated part
of the Sweet Spring Valley (No. 8, page 63.)

[The excess of carbonic acid, which unites with lime and renders
the compound soluble in water, is lost by exposure of the calcare-
ous water to the air, as well as by evaporation to dryness. \_Ac-
cum's Chemistry — Lime.~\ The masses of soft calcareous rock
which are deposited in the rapids of lime-stone streams are exam-
ples of the loss of carbonic acid from exposure to the air ; and the
stalactites in caves, the deposit of the slow-dropping water holding
in solution the super-carbonate of lime, are examples of the same
effect produced by evaporation. A similar deposit of insoluble
carbonate of lime, from both these causes, is necessarily made on
all land subject to be flooded by lime-stone waters.]

such, has been placed in my cabinet. This shell was part of the dressing
spread upon the field for the crop of 1821, and had been since exposed to
all the vicissitudes of tillage and of weather for nearly twenty-two years.
—1842.]

LIME IN WOOD ASHES.

81

9tb. All wood ashes contain salts of lime (and most kinds in
large proportions), which could have been derived from no other
source than the soils on which the trees grew. The lime thus ob-
tained from ashes is principally combined with carbonic acid, and
partly with the phosphoric, forming phosphate of lime. The
table of Saussure's analyses of the ashes of numerous plants,* is
sufficient to show that these products are general, if not universal.
The following examples of some of my own few examinations indi-
cate that ashes yield calcareous earth in proportions suitable to
their kind, although the wood grew on soils destitute of that in-
gredient— as was ascertained with regard to each of these soils.

CARBONATE

PHOSPHATB

100 GRAINS OF ASHES FROM

WHAT SOIL TAKEN FROM.

OP

OP

LIME.

LIME.

Whortlebeiry bushes, the

entire plants, except the

leaves,

Acid silicious loam,

4 grains.

4 grains.

Equal parts of the bark.

heart, and sap-wood of

an old locust,

The same,

51 **

18 «

Young locust bushes entire

Rich neutral clay loam,

40 "

30 «*

Young pine bushes.

Acid silicious loam,

9 "

6 "

Body of a young pine tree.

Acid clay soil,

14 "

18 "

Body of a white oak sap-

ling,

Stiff whitish clay, acid

70 of both. 1

and poor,

f

The potash was first carefully taken out of all these samples.
The remaining solid matter was silicious sand and charcoal j the
proportion of the latter varying according to the degree of heat
used in burning the wood, which was not permitted to be very
strong, for fear of converting the calcareous earth into quick-lime.f

■5^ Quoted in Davy's Agr. Chem. Lecture 3.

f [In the first sketch and earliest publication of this essay in the
** American Farmer," of 1821, the statement of the calcareous contents of
ashes, similar to the above, was followed by the following remark: "The
results of the few examinations I have made do not confirm the opinion
[or results] of De Saussure, that ashes yield quantities of calcareous earth
somewhat proportioned to the quantities contained in the soils from which
they were taken. But they show, in different plants, quantities suited to
the soil which each prefers. Thus, of three kinds of ashes from the same
soil, those of pine gave 5^, of whortleberry 4, and of locust 51 per cent,
of carbonate of lime, and [somewhat] similar proportions of other salts
of lime." [Am. Far. iii., p. 316.) In all the succeeding separate editions
of the essay, this remark was suppressed, being deemed too presumptuous
for me to use. But I may now dare to reassume the position, since John-
ston denies the accuracy of De Saussure's and also of Berthicr's analyses,
which concur in the conclusions referred to, and also the coiTectness of theso

82 LIME IN WOOD ASHEg.

It must be evident and unquestionable that all the carbonate of
lime yielded by the ashes had been necessarily furnished in some
form by the soil on which the plants grew; and when the soil
itself contained no carbonate, as in all these cases, some other
compound of lime must have been present, to enable us to account
for these certain and invariable results. The presence of a com-
bination of lime with some vegetahle acid, and none other, would
serve to produce such effects. According to established chemical
laws, if any such combination had been taken up into the sap-
vessels of the tree, it would be decomposed by the heat necessary
to convert the wood to ashes ] the acid would be reduced to its
elementary principles, and the lime would immediately unite with
the carbonic acid (which is produced abundantly by the process
of combustion), and thus present a product of carbonate of lime
newly formed from the materials of the other substances decom-
posed.*

On the foregoing facts and deductions, I am content to rest the
truth of the existence of acid and neutral soils.

NOTE.

Scientific Confirmation of the doctrine of Acid in Soih.

[1835. I have chosen to leave all the preceding part of this
chapter (with the exception of a few merely verbal corrections and
alterations) precisely as it appeared in the previous edition of this

conclusions. He adds the follawing words, "vvhicli, in connexion Tvith his
context, show that his opinion concurs with my position, that (supposing
enough lime to be present) the proportion in the ashes of plants is accord-
ing to the nature and demand for lime, of the particular plant; and not to
the great abundance or scarcity of lime in the soil producing the plant.
He says— "the ash of the same plant, if ripe and healthy, is nearly the
same in kind and quality in whatever circumstances (if favourable) of soil
or climate it may grow." (p. 244.) That chemists now generally admit
De Saussure's conclusions to be erroneous may also be safely inferred
from this : the many results of the ashes of plants which have appeared
in recent works, are rarely (if ever) accompanied by any report of the
contents of the soil whence derived; thus showing that the calcareous or
other ingredients are inferred to be according to the kind of plant, and
not dependent on the character of the soil. — 1849,]

* The reasoning on the presence of the carbonate of lime found in
ashes from acid soils, does not apply to the phosphate of lime which is also
always present. The latter salt is not decomposed by any known degree
of heat [Art. Chemififry^in Edin. Ency.'\^ and therefore might possibly hav«
remained unchanged, in passing from the soil to the tree, and thence to the
ashes.

HUMIC ACID. ^ 83

essay, (January 1832.)* But since that time I have first heard of
a discovery, and of consequent investigations by men of science,
which seem to furnish direct proof of what I have been contending
for, viz. the existence of a vegetable acid substance in soils and
manures, generally diffused, and often in large proportions, and
yet which had not been known or suspected by chemists previously.
The first intimation of this discovery which reached me was in an
extract in a newspaper from the ^^ Alphabet of Scientific Gar-
dening," by Professor Rennie, published in London in 1833, from
which the part relative to this subject will be quoted below.
Since, I have seen the French version of the late work of Berze-
lius, in which his views of humic acid (or, as he names it, the geic
acid) are given more at length. f The facts respecting humic
acid, as concisely stated in the following quotation from Professor
Rennie, furnish strong confirmation of some of the opinioi»s which
I have endeavoured to maintain. It will however be left, without
farther comment, for the reader to observe the accordance, and to
make the application.

^^ Humic acid and huniin. — In most cliemical books the terms ulmic acid
and ulmin are used, from ulniits, elm ; but, as its substance occurs in most,
if not all plants, the napie is bad. I prefer Sprengel's terms, from humus,
soil.

*'This important substance was first discovered by Klaproth, in a sort
of gum from an elm ; but it has since been found by Berzelius in all barks ;
by M. Braconnot in saw-dust, starch, and sugar; and, what is still more
interesting for our present purpose, it has been found by Sprengel and JNI.
Polydore Boullay to constitute a leading principle in soils and manures.
Humin appears to be formed of carbon and hydrogen, and the humic acid
of humin and oxygen. Pure humin is of a deep blackish brown, without
taste or smell, and water dissolves it with great difficulty and in small
quantities ; consequently it cannot, when pure, be ayailable as food for
plants.

" Humic acid, however, which, I may remark, is not sour to the taste,
readily combines with many of the substances found in soils and manures,
and not only renders them, but itself also, easy to be dissolved in water,
which in their separate state could not take place. In this way humic acid
will combine with lime, potass, and ammonia, in the form of humates, afid the
smallest portion of these will render it soluble in ivater and fit to be taken up by
the spongelets of the root fibres.

' ' It appears to have been from ignorance of the important action of the
humic acid in thus helping to dissolve earthy matters, that the older
writers were so puzzled to discover how lime and potass got into plants ;
and it seems also to be this, chiefly, which is so vaguely treated of in the
ft

'^' The general positions and views taken as to acid and neutral soils are
also, in substance and purport, just as they appeared in my first publica-
tion on this subject, in 1821.

f A long extract from Berzelius' *' Traite de Chimie,'^ embracing these
views, was translated for and published in the two pVeceding editions of
this essay, and also in the Farmer's Register. It is omitted now as un-
necessary.— 1849.

84 HUMIC ACID.

older books, under the names of extractive, vegetable, extract, mucilaginous
matter, and the like. Saussure, for instance, filled a vessel with turf, and
moistened it thoroughly with pure water, when by putting ten thousand
parts of it by weight under a heavy press, and filtering and evaporating
the fluid, he obtained twenty-six parts of what he termed extract; from
ten thousand parts of well dunged and rich kitchen garden mould, he ob-
tained ten parts of extract ; and from ten thousand parts of good corn field
mould, he obtained four parts of extract.

"M. Polydore Boullay found that the liquid manure, drained from
dunghills, contains a large proportion of humic acid, which accounts for
its fertilizing properties so well known in China and on the continent; and
he found it also in peat earth, and in varying proportions in all sorts of
turf. It appears probable, from Gay-Lussac having found a similar acid
(technically azumic acid), on decomposing the prussic acid (technically
hydro-cyanic acid), that the humic acid nwij be found in animal blood, and
if so, it will account for its utility as a manure for vines, &c. Dobereiner
found the gallic acid convertible into the humic."

[When the second edition of this essay was published (in 1835),
the above annunciation had but just before been made, ishowing
that there was indeed high scientific authority for the very general
existence of a vegetable acid in soils. And since that time, the
fact has been admitted by almost all scientific writers, and has
been treated of at length in sundry chemical works and reports of
p geological surveys in this country. The doctrine of the existence
of an acid of soil, of vegetable origin, which before had scarcely
, any other authority for its support than mine, humble and obscure
\ as that was, is now of universal acceptation. Still, notwithstand-
"" ing all that has been written on the subject, very little light has
been thrown on it by the chemists who have treated of it. Being
myself too little informed to be able to properly digest these
difi"erent speculations and to balance authorities, and to separate
the true and valuable from the erroneous or worthless of what has
been lately published, I deem it best still to rely on my own pre-
viously published views and proofs only, as presented in the fore-
going pages. Therefore, leaving it to chemists to settle their
present differences of opinion in regard to the qualities, and even
identity, as well as name of the acid of soil, and to clear away the
existing confusion and obscurity of their views, I will, for the
present, adopt nothing on their authority in this respect. Still, I
earnestly hope that their subsequent investigations may be success-
ful in eliciting and determining what is true of this acid — and also
in applying the truths ascertained to advance the knowledge of the
composition and improvement of soils. For the same reason, I
shall also decline adopting any of the various terms which have
been successively applied by different, and even the same chemists,
J to designate the acid of soil ) as humic, geic, ci^enic, and a/pocrenic
acid., &c.— 1842.]

[Long after the publication of the latest of the passages of the
foregoing chapter, I first learned the existence of good and sufiicient

J

thaer's publication op views. 85

autliority, in a work of deservedly high reputation, for mj doctrine
of acid soils. This is Thaer's '^Principles of Agriculture/' of j
which the English translation was first published in the United
States in 1846, (in Skinner's '^ Farmers' Library/') and which
permitted my earliest access to the work. The portion on humus
testifies positively and fully to the existence of acid soils, and also
to such results therefrom as I have maintained. At what time
these particular and important views of Thaer were first published,
does not appear; though it may be inferred, as almost certain, that
it was subsequent to the discovery and early observations of humic
acid of Sprengel and Boullay, as stated above in the article quoted
from Rennie's publication of 1833. The preface to the translation
of Thaer' s work states that the original was first published in Ger-
many, in successive numbers, from 1810 to 1812. But a work of
£his kind, in every succeeding edition, would undoubtedly receive
from its author such additions and alterations as would keep pace
with the progress of agricultural and chemical science. In pre-
senting the doctrine of acid in soil, Thaer does not claim the im-
portant discovery as his own, nor has he ever been quoted as the
first discoverer, or even as one among the earlier investigators.
Neither does he refer to other names, as authorities (as Kennie
has done above), which would naturally have been done if it was
then a discovery so recent as to require such authentication. These
would be enough reasons for inferring that Thaer's statements
on this subject are of date much later than his first edition. There
is another strong reason for this position. If he had announced
the existence of acid in soils in his earliest edition, it would have
been prior to the earliest elaborate and very able works on agri-
cultural chemistry, by Davy and Chaptal. It is incredible that
both these distinguished investigators should have passed over such
evidence, if in existence, and upon such high agricultural authority
as Thaer's, without the slightest notice,, and (as before stated)
without making any allusion to the existence of humic or any
other vegetable acid as a very general ingredient of soils. Indeed
there is direct proof that Thaer's work was a later publication than
Chaptal's, as the latter is quoted from in the former, in the portion
entitled " Theory of Soils.'' For each and all these reasons, it is
impossible that Thaer's notice of humic acid could have been as
early as his first edition ; and very improbable that it should have
been as early as Professor Ronnie's statement copied above.

But whatever was their date, the following passages from Thaer
ofi*er confirmation of my views of acid soils more full and complete
than to be seen in any other author within my observation, and
which, therefore, are doubly welcome, as the testimony of so pro-
found and distinguished an investigator,
8

;

80 THAEll ON HUMIC ACID IN SOIL.

" Humus" is the term used by this author for the decomposed
vegetable and other organic matter which is more or less mixed
with all surface soil, and which gives to soil all its fertility, and
furnishes all the food of plants. He continues : —

"It is the residue of animal and vegetable pntrefaction, and is a black
body; -when dry it is pulverulent, and when wet has a soft, greasy feel." —
"It is the produce of organic power — a compound of carbon, hydrogen,
nitrogen, and oxygen, such as cannot be chemically composed," &c. p. 534.

" When humus remains constantly damp, without, however, being covered
with water, it forms a very unpleasant smelling acid, which is more parti-
cularly characterized by the property which it possesses of colouring blue
litmus paper into red. This^ circumstance has long been known, and it is
the reason that land and meadows which are not properly drained, and
which exhibit these phenomena, are called sour. We have carefully exa-
mined these facts, and have endeavoured to discover the peculiar constitu-
tion of this acid. At first, we were inclined to regai-d it as being of a dis-
tinct nature, and having carbon for its base ; but we have since become
convinced that it is generally composed of acetic acid, and occasionally
contains a portion of the phosphoric. This latter always adheres so firmly
to the humus that it cannot be separated from it either by boiling or wash-
ing. The liquid in which the humus is boiled certainly acquires a slight
acid flavour, but the greater part of the acid remains attached to the hu-
mus."— " This acid or sour humus is not at all of a fertilizing nature ; on the
contrary, it is prejudicial to vegetation.'^ Where it is very strong and per-
vades the whole of the humus, the soil only produces reeds, rushes, sedge,
and other useless, unpalatable plants ; and whenever these abound, it may
be inferred that the soil contains a great deal of sour or acid humus. "f —
" There are various means of getting rid of this baneful property, and
rendering the humus fertile." — "It is well known that with the aid of al-
kalies, ashes, lime, and marl, humus may be deprived of its acidity, and
rendered easily soluble." — "Heaths do not thrive where this [acid] humus
does not exist, and when they have established themselves in one particular
spot, they suffer few other plants to appear. This humus may be changed
by a dressing composed of marl, lime, or ammonia ; and where this has
been mixed with the soil, the heaths, &c., speedily perish." (p. 538-9.)

" In the greater number of cases, peat is very much like acid or sour
humus ; indeed, it sometimes resembles it so strikingly that it is impossible
to distinguish these substances apart." (p. 540.)

"In both the kinds of land we have been considering [i. e., classes of
very fertile soil, rich in humus], we have supposed the humus to be mild, or
exempt from acidity. X Sour or acid humus totally destroys the fertility of a
soil ; sometimes, however, the soil contains so very small a portion of acid-
ity that its fertility is very slightly diminished, and only with regard to
some few plants. Barley crops become more and more scanty in propor-
tion as the acidity is increased ; but oats do not appear to be at all affected
b}^ it. Rye grown on such land is peculiarly liable to rust, and is easily
laid or lodged. The grains of all the cereals become larger, bilt contain

* Even to this day, Von Thaer is the only agricultural chemist known,
who affirms, with me, this important evil quality of the acid of soil. — E. R.

f These, of course, are like our broom-gi-ass, sorrel, poverty grass, pine,
&c., of the general class of what I called acid plants. Heath is another,
and the most abundant in Europe, though not existing in America, — E. R,

X Which, according to my vttws and language, would be expressed by the
actd of the soil having been neutralized by lime. — E. R.

DEDUCTIONS FROM FOREGOING DOCTRINES. 87

less farina. Grass which grows on these spots is, both in species and taste,
less agreeablp, and less suitable for cattle, than any other, although it yields
a very considerable produce in hay. In fact, in exact proportion with the
increase of acidity, is the decrease of the value of the soil," &c.

[If the foregoing examinations of soils, and the arguments which fol-
low, remain unquestioned, these two remarkable and important facts
may be considered as thereby established beyond dispute or doubt :

1st. That calcareous earth, calx, or carbonate of lime, is in gene-
ral as entirely deficient in the soils of Virginia, as that ingredient
had heretofore been supposed, by agricultural writers, to be com-
mon in all soils ; and,

2d, That, notwithstanding this total absence of the carbonate of
lime, lime in some other form of combination, and in greater or less
quantity, is an ingredient of every soil capable of producing vegetation.

Nor do these facts come in conflict with each other ; nor either
of them with the position which has been contended for, that calca-
reous matter in proper proportions is necessary to cause fertility in
soils. Should some other person, who may be aided by sufficient
scientific light, undertake the investigation, he may supply all that
is wanting for the direct proof of this theory of the cause of fer-
tility, and perhaps show that the productive value of a soil (under
equal circumstances) is in proportion to the quantity of the vege-
table salts of lime present in the soil. The direct and positive
proof of this doctrine, I confidently anticipate will hereafter be ob-
tained from more full examinations of the humic acid, and its com-
pounds in various soils, and from correct and minute reports of the
quantities and kinds of those ingredients, in connexion with the
degree of the natural fertility of each soil. As yet, however in-
teresting the recent discovery of humic acid may be to chemists, it
does not seem that they have suspected it to have anything like
the important bearing on the fertilization of soil which I had attri-
buted to the supposed acid principle or ingredient of soils. Ber-
zelius seems scarcely to have bestowed a thought on this most im-
portant application of his investigation of the properties of geine
and geic acid. — 1842.] [Other authors deem not only humin but
also humic acid as directly fertilizing to soils, and beneficial to /
plants ; which, as to this, or any other uncombined acid, is altogether
opposed to my views.* — 1849.] '

* Confirmatory testimony. — After treating extensively of different acids
of soils (humic, ulmic, crenic, apocrenic, and medusous), Johnston adds^:
" Besides these acids, it is known that the malic and acetic are occasionally
produced in the soil during the slow decay of vegetable matter of different
kinds. It is probable that many other analogous compounds are likewise
•formed — which are more or less solubfe in water, and more or less fitted to
aid in the nourishment of plants:' (p. 280.) The last words of the passa^

88 FORMATION OP ACID IN SOIL.

Supposing the doctrine to be sufficiently established by my own
proofs offered above, it may be useful to trace the formation and
increase of acidity in different soils, according to the views which
have been presented, and to display the promise which that quality
holds out for improving those soils which it has heretofore rendered
barren and worthless.

Every neutral soil at some former time must have contained cal-
careous earth in sufficient quantity to produce the uniform effect
of that ingredient of storing up and fixing fertility. [It was then
a calcareous soil, however small might have been the proportion of
free carbonate of lime co^itained.] The decomposition of the suc-
cessive growths of plants, left to rot on the rich soil, continually
formed vegetable acid, which, as fast as formed, united with the
lime in the soil. At last these two principles balanced each other,
and the soil was no longer calcareous, but neutral. Instead of its
/ former ingredient, carbonate of lime, it was now supplied with a
y vegetable salt of lime. This change of soil does not affect the na-
tural growth, which remains the same, and thrives as well as when
the soil was calcareous ; and when brought into cultivation, the
soil is equally productive under all crops suited to calcareous soils.
If the supplies of vegetable matter continue, the soil may even be-
come acid in some measure, as may be evidenced by the growth of
sorrel — but without losing any of its fertility before acquired. The
degree of acidity in any one soil frequently varies ; it is increased
by the growth of such plants as delight to feed on it, and by the
decomposition of all vegetable matters. Hence the longer a poor
field remains at rest, and not grazed, the more acid it becomes ; and
this evil keeping pace with the benefits derived, is the cause why so
little improvement, or increased product, is obtained from putting
acid soils under that mild treatment. Cultivation not only pre-
vents new supplies, but also diminishes the acidity already present

of course I oppose ; deeming all acid products of soil, alone, as injurious to
fertility and productiveness of the land for useful crops.

Besides tiie state of carbonate, Jolinston says that lime exists in fertile
soils as chloride of calcium (muriate of lime), as sulphate, phosphate,
silicate, or humate of lime. "In combination with humic acid, lime exists
most frequently in soils which abound in vegetable matter — in peaty soils,
for example, to which lime or marl have been added, -x- * * Few in-
vestigations have as yet been made in regard to the proportion of lime
which exists in the soil in the state of humate. It has generally been taken
for granted, either that a soil was destitute of lime, if it exhibited no sensible
effervescence with dilute muriatic acid, or, when further research was
made, and the quantity of lime rigorously determined, that the ivhole of this
time must have existed in the state of carbonate. That this is not necessarily
the case, however, appears to be proved by some recent examinations of
certain soils in Normandy, which contain as much as 14 to 15 per cent,
of lime, and yet exiiibit no effervescence, and contain no carbonate. The
whole of the lime is said to be in the state of humate. (p. 230-1.— 1819.]

LIME PRESENT IN ALL SOILS, NOT BARREN. 89

in excess, by exposing it to the atmosphere ; and therefore the
more a soil is exhausted of its fertility, the more will also be less-
ened its acidity, [in absolute quantity ; though not relatively to its
degree of fertility, which will be lessened still more.]

We have seen from the proof furnished by the analysis of wood
ashes, that even poor acid soils contain a little salt of lime, and
therefore must have been slightly calcareous at some former time.
But such small proportions of calcareous earth were soon equalled,
and then exceeded, by the formation of vegetable acid, before
much productiveness was caused. The soil being thus changed,
the plants suitable to calcareous soils died off, and gave place to
others which produce, as well as feed and thrive on, acidity. Still,
however, even these plants furnish abundant supplies of vegetable
matter, sufficient to enrich the land in the highest degree ; but the
antiseptic power of the acid prevents the leaves from rotting for
years, and even then the soil has no power to profit by their pro-
ducts. Though continually wasted, the vegetable matter is continually
again forming, and always present in abundance; but must remain
almost useless to the soil, until the accompanying acidity shall be
destroyed.

[It may well be doubted whether any soil destitute of lime in
every form would not necessarily be a perfect barren, incapable of
producing a spire of grass. No soil thus destitute is known, as the
plants of all soils show in their ashes the presence of some lime.
But it is probable that our sub-soils, which, when left naked by the
washing away of the soil, are so generally and totally barren, are
made so by their being entirely destitute of lime in any form.
There is a natural process regularly and at all times working to de-
prive the sub-soil of all lime, unless the soil is abundantly supplied.
What constitutes soil, and makes the strong and plain mark of
separation and distinction between the more or less fertile soil and
the absolutely sterile sub-soil beneath ? The most obvious cause
for this difference which might be stated, is the dropping of the
dead vegetable matter on the surface ; but this is not sufficient
alone to produce the effects, though it may be so when aided by
another cause of more power. When the most barren surface
earth was formed or deposited by any of the natural agents to
which such effects are attributed by geologists, it seems reasonable
to suppose that the surface was no richer than any lower part of
the whole upper stratum so deposited. If, then, a very minute
proportion of lime had been equally distributed through the body
of poor earth to any depth that the roots of trees could penetrate,
it would follow that the roots would, in the course of time, take up
all the lime, as all of it would be wanting for the support of the
trees ; and their death and decay would afterwards leave all this
former ingredient of the soil, in general, on the surface. This
8*

90 DORMANT FERTILITY OF UNPRODUCTIVE LANDS.

process must have the effect, in the course of time, of fixing on
and near the surface the whole of a scanty supply of lime, and of
leaving the subsoil without any. But if there is within the reach
of the roots more lime than any one crop or growth of plants
needs, then the superfluous lime will be permitted to remain in the
sub-soil, which sub-soil will then be improvable by vegetable sub-
stances, and readily convertible to productive soil. The manner
in which lime thus operates will be explained in the next chapter.
—1835.]

Nearly all the woodland now remaining in lower Virginia, and
also much of the land which has long been arable, is rendered un-
productive by acidity ; and successive generations have toiled on
such land, almost without remuneration, and without suspecting
that their worst virgin land was then richer than their manured
lots appeared to be. The cultivator of such soil, who knows not
its peculiar disease, has no other prospect than a gradual decrease
of his always scanty crops. But if the evil is once understood,
and the means of its removal are within his reach, ^le has reason
to rejoice that his soil was so constituted as to be preserved from
the eifccts of the improvidence of his forefathers, who would have
worn out any land not almost indestructible. The presence of
acid, by restraining the productive powers of the soil, has in a
great measure saved it from exhaustion ; and after a course of
cropping which would have utterly ruined soils much better con-
stituted, the powers of our acid land remain not greatly impaired,
though dormant, and ready to be called into action by merely being
relieved of its acid quality. A few crops will reduce a new acid
field to so low a rate of product, that it scarcely will pay for its
cultivation ; but no great change is afterwards caused, by continu-
ing scourging tillage and grazing, for fifty years longer. Thus our
acid soils have two remarkable and opposite qualities, both pro-
ceeding from the same cause : they can neither be enriched by ma-
nure, nor impoverished by cultivation, to any great extent. Quali-
ties so remarkable deserve all our powers of investigation; yet
their very frequency seems to have caused them to be overlooked ;
and our writers on agriculture have continued to urge those who
seek improvement to apply precepts drawn from English authors,
to soils which are totally diifercnt from all those for which their
instructions were intended.*

[* Confirmatory testimony. — Professor Johnston affirms that lime is indis-
pensable to the fertility of soils, as I have done. But he goes still farther
than what is true, at least as to America, in the following passage: " The
results of all the analyses hitherto made of soils naturally fertile, show
that lime is universally present. The percentage of lime in a soil may be
very small, yet it can always be detected when valuable and healthy crops
will grow upon it. Thus the fertile soil of the

TESTIMONY OF J. C. LOUDON- 91

TVIarsh lands of Holstein contains 0.2 per cent, of carbonate of lime.

Salt marsh iu East Friesland .0.6 " "

Rich pasture near Durham .1.31 " **

But though the percentage of lime in these cases appears small, the ab-
solute quantity of lime present in the land is still large. Thus, suppose
the first of these soils, which contains the least, to be only six inches deep,
and each cubic foot to weigh only 80 lbs. — it would contain about 3500 lbs.
of carbonate of lime to every acre." — Though the author at first speaks of
"Zme" as universally present in very fertile soils, it is clear, from the con-
text, that he meant carbonate of lime. In succeeding passages he claims
the presence of lime in all producing soils, upon the same grounds that I
did, viz. : the presence of lime in all ashes of plants. (Johnston's Lectures,
pp. 378-9.)

It is intei'esting to compare this recent admission of .Johnston, j)f even
more than I claimed (or would admit), and the now general acceptation of
the true doctrine, with the following expressions of the late J. C. Loudon,
perhaps then. the highest agricultural authority in England, if not in all
Europe. Both the passages were editorial, in his "Gardener's Magazine"
for 1836. The first is part of a short notice of the first edition of this
essay (of 1832), which had been "pirated," garbled, and disguised by the
editor of the "British Farmer's Magazine," and so published, as if a com-
munication to that periodical. In this notice Mr. Loudon copies the heads
of my five propositions, and says — " These propositions contain the mar-
row of the Essay, which is closely reasoned, and in several particulars
original. Mr. Ruffin has the merit of first pointing out that tliere can be
no such thing as naturally fertile soil without the presence of calcareous
earth ; but where this earth is present, the soil, however exhausted it may
have been by culture, will, when left to itself, after a time regain its origi-
nal fertility ; that soils which contain no calcareous earth are never found
naturally fertile, .... and that all that art can do to them, exclusive of
adding calcareous earth, is to force crops by putrescent manures ; but that
when these manures are withheld, the soil will speedily revert to its origi-
nal sterility. Mr. Ruffin observes that no agricultural or chemical writer
ever denied these facts ; but, he asserts, a?id we think with truth, that by
not one of them have they ever been distinctly stated. We are not quite
certain as to Grisenthwaite, but -vf e are so as to I^rwan, Dundonald, Davy,
Chaptal, and other agricultural chemists of the continent. ... It is due to
INIr. R;uffin to state it as our opinion, that he has performed a very important
service to the scientific agriculturist in this country, as well as in America."

And again, in a subsequent long ^editorial article, noticing all the im-
portant and valuable discoveries or new improvements in agriculture during
the preceding year, Mr. Loudon says —

"In agricultural science, the only point that we can recollect worthy of
notice, that has occurred during the past year, is the advancement of the
principle by the American agricultural writer, Mr. Ruffin, that no soil
whatever will continue fertile for any length of time that does not contain
calcareous matter. This we believe was never distinctly stated as a prin-
ciple by Kirwan, Chaptal, Davy, or any other European chemist or agri-
culturist. "—1 849. ]

;

CHAPTER VIII.

THE MODE OF OPERATION BY WHICH CALCAREOUS EARTH IN-
CREASES THE FERTILITY AND PRODUCTIVENESS OF SOILS.

Proposition 3. — The fertilizing effects of calcareous earth are
chiefly produced hy its poiver of neutralizing acids, and of com-
bijiing putrescent manures loith soils, hetweeji lohich there would
otherwise he hut little, if any, chemical attraction.

Proposition 4. — Poor and acid soils cannot he improved durahly,
or profitably, hy putrescent manures, without previously making
them calcareous, and thereby correcting the defect in their con-
stitution.

It has already been made evident that the presence of calcareous
earth [in small proportion, or not in too great excess], in a natural
soil, causes great and durable fertility. But it still remains to be
determined, to what properties of this earth its peculiar fertilizing
effects are to be attributed.

Chemistry has taught that silicious earth, in any state of divi-
sion, attracts but slightly, if at all, any of the parts of putrescent
animal and vegetable matters.* But even if any slight attraction
really exists when this earth is minutely divided for experiment in
the laboratory of the chemist, it cannot be exerted by silicious
sand in the usual form in which nature gives it to soils ; that is,
in particles comparatively coarse, loose, and open, and yet each
particle impenetrable to any liquid, or gaseous fluid, that might be
passing through the vacancies. Hence, silicious earth can have
no power, chemical or mechanical, either to attract enriching
manures, or to preserve them when actually placed in contact and
intermixed with them ; and soils in which the qudities of this
earth greatly predominate, must give out freely all enriching mat-
ters which they may have received, not only to a growing crop, but
to the sun, air, and water, so as soon to lose the whole. No por-
tion of putrescent matter can remain longer than the completion
of its decomposition ; and if not arrested during this process, by
the roots of living plants, all will escape in the form of gas (the
latest products of decomposition), into the air, without leaving a
trace of lasting improvement. With a knowledge of these pro-
perties, we need not resort to the common opinion that manure iS

* Davy's Agr. Chem. page 129.

(92)

SINKING OP MANURES, THROUGH SOILS AND SUB-SOILS. 93

lost bj- sinking tlirougli sandy soils, to account for its usually rapid
and total disappearance.*

Aluminous earth, by its closeness, mechanically excludes those
agents of decomposition, heat, air, and moisture, which sand so
freely admits ; and therefore clay soils, in which this earth pre-
dominates, give out manure much more slowly than sand, whether
for waste or for use. The practical effect of this is universally
understood — that clay soils retain manure much longer than sand,
but require much heavier applications to show as much effect early,
or at once. But as this means of retaining manure is altogether
mechanical, it serves only to delay both its use and its waste.

* Except the very small proportions of earthy, saline, and metallic mat-
ters that may be in animal and vegetable manures, the whole remainder of
their bulk (and the whole of whatever can feed plants) is composed of
different elements which are known only in tlie forms of ffases — into which
manures must be finally resolved, after going through all the various stages
of fermentation and decomposition. So far from sinking in the earth, if in
quantity, these final results could not be possibly confined there, but must
escape into the atmosphere as soon as they take a gaseous form, unless
immediately taken up by the organs of growing plants, [or unless held by
the soil's absorbing chemical power,] It is probable, however, that but a
small portion of any dressing of manure remains long enough in tlie soil
to make this final change ; and that nearly all of it is used by growing
plants, during previous changes, or carried ofi^ by air and water. [During
the progress of the many changes caused by fermentation and decomposi-
tion, every portion of the manure fit for use, becomes soluble. When in
the soluble state only, it is ready for the use of plants ; and if not then so
used, is as ready to be wasted, if the soil has not enough of attracting and
combining power to hold the soluble products. I infer that it depends
mainly, if not entirely, on the presence or absence of such chemical power
in a sandy soil, with also a sandy or other pervious sub-soil, whether the
soluble products of putrescent manures are lost by sinking. If there is
not enough such power in the soil — (that is, if it contains very little lime
in any state)-- and there is too much manure in a soluble state for the roots
of growing plants to take up immediately, then the remainder will be dis-
solved in the first rain, and follow the course of the excess of water,
whether to flow off the surface, or to sink deep into the sub-soil. Of so
much as thus sinks, the further decomposition and final conversion to gases
must be retarded by the greater seclusion from heat and air. In the mean
time, the substance continues to be soluble, and liable to be again carried
deeper, by successive heavier rains, until, with their excess of water, pene-
trating to the sources of springs, either temporary or permanent, and thus
passing into the streams. We know that springs are thus supplied by the
rains, and that their waters are in many cases polluted by organic as well
as mineral soluble matters. This waste by sinking, even of the fertile
parts of natural or unmanured soil, is manifest on tilled land of which the
pervious sub-soil needs and has failed to receive drainage. In such cases,
the water below is oozing away after every wet spell ; and sometimes the
soil disappears as if washed away, though having neai'ly a level surface.
The dai'k-coloured organic and alimentary parts only have been thus re-
moved, leaving that which had been soil as poor as its sub-soil. — 1849.]

94 RELATIONS OF CLAY AND CALX TO TUTRESCENT MANURES.

Aluminous earth also exerts some chemical power in attracting
and combining with putrescent manures, but too feebly to enable
a clay soil to become rich by natural means. [For though clays
are able to exert more force than sands in holding manures, their
closeness also acts to deny admittance beneath the surface to the
enriching matters furnished by the growth and decay of plants.
And therefore, before being brought into cultivation, a poor clay
soil would derive scarcely any benefit from its small power of com-
bining chemically with putrescent matters. If then it is con-
sidered how small is the power of both silicious and aluminous
earths to receive and retain putrescent manures, it will cease to
cause surprise that such soils cannot be thus enriched, with profit,
if at all. It would indeed be strange and unaccountable, if earths
and soils thus constituted could he enriched by putrescent manures
alone. — 1835.] ^

Davy states that both aluminous and calcareous earth will combine
with any vegetable extract, so as to render it less soluble (and con-
sequently not subject to the waste that would otherwise take place),
and hence " that the soils which contain most alumina and carbo-
nate of lime, are those which act with the greatest chemical energy
in preserving manures.^' Here is high authority for calcareous
earth possessing the power which my argument demands, but not
in so great a degree as I think it deserves. Davy apparently places
both earths in this respect on the same footing, and allows to
aluminous soils retentive powers equal to the calcareous. But
though he gives evidence (from chemical experiments) of this
power in both earths, he does not seem to have investigated the
difierence of their forces. Nor could he deem it very important,
holding the opinion which he elsewhere expresses, that calcareous
earth acts '' merely by forming a useful earthy ingredient in the
soil,'' and consequently attributing to it no remarkable chemical
effects as a manure. I shall offer some reasons for believing that
the powers of attracting and retaining manure, possessed by these
two earths, differ greatly in their degrees of force.

The aluminous and calcareous soils of this country, through the
whole of their virgin state, have had equal means of receiving
vegetable matter ; and if their powers for retaining it were nearly
equal, so would be their acquired fertility. Instead of this, while
the calcareous soils have been raised to the highest condition, many
of the tracts of clay soil remain the poorest and most worthless.
It is true that the one laboured under acidity from which the other
was free. But if we suppose nine-tenths of the vegetable matter
to have been rendered useless by that poisonous quality, the re-
maining tenth, applied for so long a time, would have made fertile
any soil that had the power to retain the enriching matter.

[Many kinds of shells are partly composed of gelatinous animal

MODE OP OPERATION OF CALX AS MANURE. 95

matter, which, I suppose, must be chemically combined with the
calcareous earth, and by that means only is preserved from the
putrefaction and waste that would otherwise certainly and speedily
take place. Indeed, the large proportion of animal matter which
thus helps to constitute some kinds of shells, instead of makiirg
them more perishable, serves to increase their firmness and solidity.
When long exposure, as in fossil shells, has destroyed all animal
matter, the texture of the calcareous substance is greatly weakened.
A simple experiment will serve to separate, and make manifest to
the eye, the animal matter which is thus combined with and pre-
served by the calcareous earth. If a fresh-water mussel-shell is
kept for some days immersed in a weak mixture of muriatic acid
and water, all the calcareous part will be gradually dissolved,
leaving the animal matter so entire, as to appear still to be a whole
shell — but which, when lifted from the fluid which supports it,
will prove to be entirely a flaccid, gelatinous, and putrescent sub-
stance, without a particle of calcareous matter being left. Yet
this substance, which is so highly putrescent when alone, would
have been preserved in combination with calcareous matter, in the
shell, for many years, if exposed to the usual changes of air and
moisture ; and if secured from such changes, would be almost im-
perishable.— 1835.]

• Calcareous earth has power to preserve those animal matters
which are most liable to waste, and which give to the sense of
smell full evidence when they are escaping. Of this, a striking
example is furnished by an experiment which was made with care
and attention. The carcase of a cow, that was killed by accident
in May, was laid on the surface of the earth, and covered with
about seventy bushels of finely divided fossil shells and earth
(mostly silicious), their proportions being as thirty-six of calcare-
ous, to sixty -four of silicious earth. After the rains had settled
the heap, it was only six inches thick over the highest part of the
carcass. The process of putrefaction was so slow, that several
weeks passed before it was over ; nor was it ever so violent as to
throw off any effluvia that the calcareous earth did not intercept
in its escape, so that no ofi'ensive smell was ever perceived. In
October, the whole heap was carried out and applied to one-sixth
of an acre of wheat — and the effect produced far exceeded that of
the like calcareous manure alone, which was applied at the same
rate on the surrounding land. No such power as this experiment
indicated (and which I have since repeated in various modes, and
always with like results), will-be obtained, or expected, from using
clay as the covering earth.

Quick-lime is used to prevent the escape of offensive effluvia
from animal matter ; but its operation is entirely different from
that of calcareous earth. The former effects its object by ^^ eating"

96 PRESERVING AND FIXING MANURES.

or decomposing the animal substance (and nearly destroying it as
manure), before putrefaction begins. The operation of calcareous
earth is to moderate and retard, but not to prevent putrefaction •
not to destroy the animal matter, but to preserve it effectually, by
forming new combinations with the products of putrefaction. This
important operation will be treated of more fully in a subsequent
chapter.

The power of calcareous earth to combine with and retain putres-
cent manure, implies the power of fixing them in any soil to
which both are applied. The same power will be equally exerted
if the putrescent manure is applied to a soil which had previously
been made calcareous, whether by nature, or by art. When a
chemical combination is formed between the two kinds of manure,
the one is necessarily as much fixed in the soil as the other.
Neither air, sun or rain, can then waste the putrescent manure, be-
cause neither can take it from the calcareous earth, with which it
is chemically combined. Nothing can effect the separation of the
parts of this compound manure, except the attractive power of
growing plants — which, as all experience shows, will draw their
food from this combination as fast as they require it, and as easily
as from sand. The means then by which calcareous earth acts as
an improving manure are, completeli/ presei^ving putrescent manures
from waste, and yielding them freely for use. These particular '
benefits, however great they may be, cannot be seen very quickly
after a soil is made calcareous, but will increase with time, and,
with the means for obtaining vegetable matters, until their accu-
mulation is equal to the soil's power of retention. The kind, or
the source, of enriching manure, does not alter the process de-
scribed. The natural growth of the soil, left to die and rot, or
other putrescent manures collected and applied, would alike be
seized by the calcareous earth, and fixed in the soil.

This, the most important and valuable operation of calcareous
earth, then gives nothing to the soil ; but only secures other ma-
nures, and gives them wholly to the soil. In this respect, the
action of calcareous earth in fixing manures in soils, is precisely
like that of mordants in " setting'^ or fixing colours on cloth.
When alum, for -example, is used by the dyer for this purpose, it
adds not the slightest tint of itself — but it holds to the cloth, and
also to the otherwise fleeting dye, and thus fixes them permanently
together. Without the mordant, the colour might have been
equally vivid, but would be' lost by the first wetting of the cloth.

[Thus, reasoning a priori from that chemical power possessed
by calcareous earth, which is wanting to both sandy and clayey
earths, would lead to the conclusion that calcareous earth serves to
combine putrescent matters v/ith the soil in general; and the
known results of fertility being therein so fixed, might serve for

NEUTRALIZINO ACIDf IN SOILS. 97

the like proof, even without the other course of reasoning. There
is still another proof of this combination being formed, which is ob-
tained by a chemical process, but which is so simple that no chemi-
c-al science is requisite to make the trial.

If a specimen of any naturally poor soil, after being dried and
reduced to powder, be agitated in a vessel of water (as a common
drinking glass), and then allowed to stand still, the coarser sili-
cious sand will subside first, the finer sand next, and last the clay.
In this manner, and by pouring off the lighter parts, before their
subsidence, it is very easy to separate with sufficient accuracy the
sand from the clay. But if a specimen of a good rich neutral soil
be tried in that manner, it will be found that the finest sand and
the clay and putrescent matter hold together so closely that they
cannot be separated by mere agitation in water. Then take another
sample of the same soil, and pour to it a small quantity of diluted
muriatic acid ; and though no effervescence is produced (the lime
not being in the form of carbonate), the acid will take away the
lime, or destroy its combination with the other earths, so that the
sand and the clay may then be separated by agitation in water, as
perfectly and easily as in the case of the poorest soils. This dif-
ference between good and bad soils (whether light or stiff), or those
naturally rich and those naturally poor, cannot escape the observa-
tion of the young experimenter; and the cause can be no other
than what I have supposed. This then serves as the third mode
of proof of the important position, that calcareous earth (or lime
in some other form) not only combines with vegetable and animal
matters, but also serves (as a connecting link) to combine these
matters with the sand and clay of the soil, — 1842.]

The next most valuable property of calcareous manures for the
improvement of soil is their jjoicer of neutralizing acids, which
has already been incidentally brought forward in the preceding
chapter. According to the views already presented, even our
poorest cultivated soils contain more vegetable matter than they
can beneficially use ; and when first cleared, they have it in great
excess. So antiseptic is the acid quality of poor woodland, that
before the crop of leaves of one year can entirely rot, two or three
others will have fallen ; and there are always enough, at any one
time, to greatly enrich the soil, if the leaves could be rotted and
fixed in it at once.

[This alleged antiseptic effect of vegetable acid in our soils re-
ceives strong support from the facts established with regard to peat
soils, in which vegetable acids have been discovered by chemical
analysis ; and though the peat or moss soils of Britain differ
entirely from any soils in eastern Virginia (except that of the
great Dismal Swamp, the only extensive peat bog known), still some
facts relating to the former class may throw light on the properties
9

98 ALTERING TEXTURE AND ABSORBENCY OF SOILS.

of our own soils, different as they may be. Not only does vcgeta'
ble matter remain without putrefaction in peat soils and bogs, and
serve to increase their depth by regular' accretions from the succes-
sive annual growths, but even the bodies of beasts and men have
been found unchanged under peat, many years after they had been
covered.* It is well known that the leaves of trees rot very
quickly on the rich lime-stone soils of the Western States (neutral
soils), while the successive crops of several years' growth, in the
different stages of their slow decomposition, may be always found
on the acid woodland of lower Virginia.
r" The presence of acid in soils, by preventing or retarding putre-
/ faction, keeps the vegetable matter inert, and even hurtful on cul-
I tivated land ; and the crops are still further injured by taking up
I this poisonous acid with their nutriment. A sufficient quantity
j of calcareous earth, mixed with such a soil, will immediately
' neutralize the acid, and destroy its powers ; and the soil, released
from this baneful influence, will be rendered capable, for the first
^^ time, of using the fertility which it really possessed. The benefit
thus produced is almost immediate ; but though the soil will show
a new vigour in its earliest vegetation, and may even double its first
crop, yet no part of that increased product is due to the direct
operation of the calcareous manure, but merely to the removal of
acidity. The calcareous earth, in such a case, has not made the
soil richer in the slightest degree, but has merely permitted it to
bring into use the enriching principles it bad before, and which
, ~ were concealed by the acid character of the soil. It will be a
! dangerous error for the farmer to suppose that calcareous earth can
j enrich soil by direct means. It destroys the worst foe of produc-
I tiveness, and uses to the greatest advantage the fertilizing powers
of other manures ) but of itself it gives no fertility to soils, nor
does it furnish the least food to growing plants. f

These two kinds of action are by far the most powerful of the
means possessed by calcareous earth for fertilizing soils. It has
another however of great importance — or rather two others, which
may be best described together as the power of altering the texture
and ahsorhency of soils.

At first it may seem impossible that the same manure can pro-
duce such opposite effects on soils as to lessen the faults of being
either too sandy or too clayey — and the evils occasioned by both
the want and the excess of moisture. Contradictory as this may

* See Alton's Essay on Moss Earth, republished in Farmers' Register,
Tol. v., p. 462.

[f Confirmation. — Lime "neutralizes acid substances, ■which are naturally
formed in the soil, and decomposes or renders harmless other noxious com-
pounds which are not unfrequently within reach of the roots of plants.'*
Johnston's Agr. Chem. p. 400.]

ALTERING TEXTURE AND ABSORBENCY OP SOILS. 99

appear, it is strictly true as to calcareous earth. In common with
clay, calcareous earth possesses the power of making sandy soils
more close and firm — and in common with sand, the power of
making clay soils lighter, or more open and mellow. When sand
and clay thus alter the textures of soils, their operation is alto-
gether mechanical; but calcareous earth must exert chemical
action in producing such effects, as its power is very far greater
than that of either sand or clay. A very great quantity of clay
would be required to stiffen a sandy soil perceptibly, and still more
sand would be necessary to make a clay soil much lighter — so that
the cost of such improvement would generally exceed the benefit
obtained. Far greater effects on the texture of soils are derived
from much less quantities of calcareous earth, besides obtaining
the more valuable operation of its other powers.*

Every substance that is open enough for air to enter, and the
particles of which are not absolutely impenetrable, must absorb
moisture from the atmosphere. Aluminous earth, reduced to an
impalpable powder, has strong absorbing powers. But this is not
the form in which such soils can act — and a close and solid clay
will scarcely admit the passage of air or water, and therefore can-
not absorb much moisture except by its surface. Through sandy
soils, the air passes freely; but most of its particles are impene-
trable by moisture, and therefore these soils are also extremely
deficient in absorbent power. Calcareous earth, by rendering clay
more open to the entrance of air, and closing partially the too
open pores of sandy soils, increases the absorbent powers of both.
To increase that power in any soil, is to enable it to draw supplies
of moisture from the air, in the dryest weather, and to resist more
strongly the waste by evaporation of light rains. A calcareous
soil will so quickly absorb a hasty shower of rain as to appear to
have received less than adjoining land of different character ; and
yet if observed in summer, when under tillage, some days after a
rain, and when other adjacent land appears dry on the surface, the
part made calcareous will still show the moisture to be yet remain-
ing, by its darker colour. All the effects from this power of calca-
reous manures may be observed within a few years after their ap-
plication— though none of them so strongly marked, as they are
on lands made calcareous by nature, and in which time has aided
and perfected the operation. These soils present great variety in
their proportions of sand and clay ; yet the most clayey is friable
enough, and the most sandy firm and close enough, to be considered
soils of good texture ; and they resist the extremes of both wet

[* Professor Johnston confirms this remarkable power of calcareous
manures to make clay soils lighter, and light soils more close ; but (strangely
enough), ascribes these opposite operations to the physical or mechanical
action of Ume. (P. 400, Agr. Chem.)— 1849.]

100 LIME AS FOOD FOR PLANTS.

and dry seasons, better than any other soils whatever. Time, and
the increase of vegetable matter, will bring those qualities to the
same perfection in soils made calcareous by artificial means, as
they are in soils made calcareous by nature.

The subsequent gradual accumulation of vegetable or other
putrescent matter in the soil, by the combining or fixing power
of calcareous earth, must have yet another beneficial effect on
vegetation. The soil is thereby made darker in colour, and it con-
sequently is made warmer, by more freely absorbing the rays of
the sun. [This must cause earlier ripening of all the vegetable
growths.]

[There is another power or function of lime in soil, indispensa-
ble to the perfection, healthy growth, and perhaps even to the ex-
istence of every plant ; and which has already been considered as
a proof of neutral soils. This is to supply, through the roots, to
every growing plant some lime in soluble state which will remain
fixed in the plant. This quantity varies with the kind of plant,
and its wants in different stages of growth ; and however varying
in different kinds of plants, even when most abundant, it is always
very small in proportion to the other (organic) matters taken up
by and retained in the substance of plants. By reducing the plant
to ashes only can the lime taken up by the roots be found, and the
proportion to the ashes and to the former vegetable substance be
known.

It may be perhaps deemed a contradiction, or drawing a distinc-
tion where there is no real difference, to afl&rm the absolute necessity
of every plant receiving through its roots, a certain proportion of
lime, however minute, and yet denying that lime serves as food for
plants. I admit the difficulty of clearly discriminating by defini-
tion between the two functions. Still, there is great difference
between the manner and results of the supply of 'lime to plants,
and of the aliment which they draw from putrescent manures,
humus, or other soluble organic matter. According to the quantity
of soluble putrescent manure supplied to or naturally in a soil
(unless so enormous as to be hurtful), so will be the quantity of
the earliest vegetable growth thereon. But if a soil has been so
moderately supplied with lime, as to be barely rendered neutral,
the subsequent addition of any greater quantity of lime will add
nothing directly, or speedily, to the production of grain or other
ordinary crops — ^nor to the quantity of lime taken up by the whole
of such succeeding growth. If a soil so destitute of organic mat-
J ter — such as is recognised by all as furnishing food to plants — as
to be nearly barren, is supplied properly and profusely with putres-
cent manures, the next growth of vegetables may be remarkable
for luxuriance and heavy product. But if this rich supply of food
had been entirely withheld; and lime or calcareous earth given

SPECIFIC MANURE FOR CERTAIN KINI)S ,i)F^ PLANETS. iO|. ;

instead, in any quantity, either a very slight increase of productive
power, or none at all, would be shown in the next immediately
succeeding attempt to produce a crop thereon. Whether then it be
correct to consider lime as food for plants, or not, it is all-important
that farmers should act, in applying calcareous manures, as if they
thereby furnished no food whatever to plants in the direct manner
that is done by dung. And great as is this error of the opposite
opinion, it has had extensive influence and very injurious conse-
quences. In the greater number of cases, where ignorant farmers
have just arrived at the before unknown truth that calcareous ma-
nures are of benefit to crops and land, they proceed immediately
to the false conclusion that they will produce benefit in the same
manner as putrescent manures ; and they apply them by the same
rules and to similar soils, in the vain expectation of in like manner
supplying food to the crops. Such course can result only in dis-
appointment and loss of means, if not injury to the land.

As has been stated, all known plants, not exeepting the acid
kinds, contain some lime, and therefore it may safely be assumed
that some lime is indispensable to the growth of every plant, and
to even the lowest productive power of every soil. But, for the
greater number of plants, the quantity of lime required is so ex-
ceedingly small, that they readily obtain their needed supplies from
soils the least supplied by nature with lime. And many plants
(like pines and sorrel) prefer the soils having such scant supply
of lime as to permit an excess of acid. Other plants require com-
paratively large supplies, such as clover, and all other of the legu-
minous or pea tribe. The ashes of these plants contain compara-
tively very large proportions of lime. Red clover, lucerne, and
still more sainfoin, cannot thrive well, except on soils largely sup-
plied with lime in some state ; though, for most of such plants,
perhaps a rich neutral soil will offer the requisite supplies of lime
as well as if calcareous, or containing carbonate of lime. Among
trees, locust, papaw, and hackberry (or sugar nut), are also plants
to which lime in considerable quantity in the soil is essential. For
all such plants, lime is a ^'pecijic manure; that is, it improves
their growth in a peculiar and remarkable degree, though none of
them can take up into their bodies more than a very small amount
of lime.

The following list, showing the proportions of lime in many
cultivated plants, is extracted and abridged from the late publica-
tion of Johnston, who copied the analyses of Sprengel. The
quantities of pure lime are here understood, without reference to
the acid (or its kind) with which the lime was combined. 1000
parts in each case of the dry vegetable matters are supposed to be
burnt to ashes, and the weights of ashes, and of the pure lime
they contain, arc only stated.
9*

102

LIME IN ASHES OF VARIOUS PLANTS.

1000 lbs. of

Grain of wheat

Straw of wheat

Grain of barley

Straw of barley

Grain of oats

Straw of oats

Grain of rye

Straw of rye

Field bean seed

Do. straw -

Field peas (English)

Do. straw

Common vetch seed {vicia sativa) [our part- ")

ridge pea?] j

Straw of same

Rye grass

Red clover

White clover

Lucerne

Sainfoin

Gives total of

11.77

35.19

23.49

52.42

26.

57.5

10.5

28.

21.36

31.21

24.64

49.71

29.9

51.1

52.86
74.78
91.32
95.53
69.57

Of which there
is lime (pure),

0.96
2.40
1.06
5.54
0.86
1.52
1.22
l!78
1.65
6.24
0.58
27.30

1.60

19.55
7.34
27.80
23.48
48.31
21.95

—1849.]

Additional and practical proofs of all these powers of calcareous
earth will be furnished, when its use and effects as manure will be
stated. I am persuaded, however, that enough has already been
said both to establish and account for the different capacities of
soils for improvement by putrescent manures. If the power of
fixing manures in soils has been correctly ascribed to calcareous
earth, that alone is enough to show that soils containing that in-
gredient, in proper quantities, must become rich; and that alumi-
nous and silicious earths mixed in any proportions, and even with
vegetable or other putrescent matter added, can never form other
than a sterile soil.*

[* The several peculiar or stronger powers for increasing fertility and
production ascribed above to calcareous earth in soil, are those which were
presented to my mind either in advance of all practical applications of the
earth as manure, or otherwise were the results of actual observation
within a few years after the commencement. The chemical laws and
agencies were of course gathered from books. The confirmatory facts
were mostly found in my observation of the characters of natural soils, and
in the earliest results of my calcareous manurings. It is not necessary
here, and would scarcely be proper, to adduce other powers of calcareous
manures, learned from much later practical results, or which have since
been presented by later and much more scientific investigators. Sundry
other useful and some very important agencies of calcareous earth in soils
may be seen in the ''Lectures on the Applications of Chemistry and
Geology to Agriculture," by J. F. W. Johnston. It is gratifying to me,
that this author in most respects sustains my doctrine ; thougli in some
points we are entirely opposed. These differences, as well as the most im-

CHAPTER IX.

ACTION OP CAUSTIC LIME AS MANURE.

The object of tliis essay is to treat only of calcareous earth (as
before defined) as a manure, and not of pure caustic lime, nor of
manures in general. Still the nature of that which is properly my
subject is so intimately connected with some other kinds of manures,
and is so liable to be confounded with others which act very dif-
ferently, that frequent references to both classes have been and
will be again necessary. To make such references more plain and
useful, some general remarks and opinions will now be submitted,
as to the peculiar modes of the operation of various manures, and
particularly of lime.

Until now I have been careful to say as little as possible oi pure
or quick-lime, for fear of my meaning being mistaken, from the
usual practice of confounding it with calcareous earth ; or of con-
sidering both its first and later operations as belonging to one and
the same manure. The connexion between the manures is so inti-
mate, and yet their actions so distinct, that it is necessary to mark
the points of resemblance as well as those of difference.

My own use of quick or caustic lime as a mginure has not ex-
tended beyond a few acres ; and I do not pretend to know any-
thing from experience of its first or caustic effects. But Davy's
simple and beautiful theory of its operation carries conviction with
it, and in accordance with his opinions I shall state the theory, and
thence attempt to deduce its proper practical use-
By a sufficient degree of heat, the carbonic acid is driven off
from shells, lime-stone, or chalk, and the remainder is pure or
caustic lime. In this state it has a powerful decomposing power
on all putrescent animal and vegetable matters, which it exerts on
every such substance in the soils to which it is applied as manure.
If the Jime thus meets with solid and inert vegetable matters, it
hastens their decomposition, renders them soluble, and brings them
into use and action as manure. But such vegetable and animal
matters as were already decomposed, and fit to support growing
plants, are injured by the addition of lime; as the chemical action

portant of other operations and values of calcareous manures which he pre-
sents, will be brought in view, and considered, at a later part of this
essay. Other passages confirming my opinions previously advanced, have
been or will be quoted in notes. — 1849- ]

(103)

104 QUICK-LIME AS MANURE.

"whicli takes place bet-ween these bodies forms different eomponnds,
which are always less valuable than the putrid or soluble matters
were, before being acted on by the lime.*

This theory will direct us to expect profit from applying caustic
lime to all soils containing much unrotted and inert vegetable
matter, as our acid wood-land when first cleared, and perhaps worn
fields, covered with broomgrass ; and to avoid the application of
lime, or (what is the same thing) to destroy previously its caustic
quality by exposure to the air, for all good soils containing soluble
vegetable or animal matters, and on all poor soils deficient in inert,
as well as in active nourishment for plants. The warmth of our
climate so much aids the fermentation of all putrescent matters in
soils, that it can seldom be required to hasten it by artificial means.
To check its rapidity is much more necessary, to avoid the waste
of manures in our lands. But in England, and still more in Scot-
land, the case is very different. There, the coldness and moisture
of the climate greatly retard the fermentation of the vegetable
matter that falls on the land ; so much so that, in certain situa-
tions, the most favourable to such results, the vegetable cover is
increased by the deposit of every successive year, and forms those
vegetable soils which are called moor, ijcat, and hog lands. Vege-
table matter abounds in these soils, and sometimes it even forms
the greater bulk for many feet in depth ; but it is inert, insoluble,
and useless, and the soil is unable to bring any useful crop, though
containing vegetable matter in such great excess. Many millions
of acres in Britain are of the different grades of peat soils, of
which almost none exist in the eastern half of Virginia. Upon
this ground of the difference of climate, and its effects on ferment-
ation, I deduce the opinion that caustic lime would he serviceable
much more generally in Britain than here ; and indeed that there
are very few cases in which the caustic quality would not do our
arable lands more harm than good. This is no contradiction to
tl^e great improvements which have been made on many farms by
applying lime ; for its caustic quality was seldom allowed to act at
all. Lime is continually changing to the carbonate of lime ; and,
in practice, no exact line of separation can be drawn between the
transient effects of the one, and the later, but durable ihiprove-
ment from the other. Lime powerfully attracts the carbonic acid
of which it was deprived by heat, and that acid is universally dif-
fused through the atmosphere (though in a very small proportion),
and is produced by every decomposing putrescent substance. Con-
sequently, caustic lime, when on land, is continually absorbing
and combining with this acid ; and, with more or less rapidity,
according to the manner of its application, is returning to its for-

* Davy's Agr. Cliem. Lect. v'lu

QUICK-LIME SOON CARBONATED. 105

mer state of mild calcareous earth. If spread as a top-dressing^
on grass lands — or on ploughed land, and superficially mixed with
the soil by harrowing — or used in composts with fermenting vege-
table matter — the lime is probably completely carbonated, before
its causticity can act on the soil. In no case can lime, applied
properly as manure, long remain caustic in the soil. Thus most
applications of limG are, in effect, and even from the beginning of
the manuring action, simply applications of calcareous earth ; but
acting with greater energy and power at first, in proportion to the
quantity, because more finely divided, and more equally distributed.

[Whether lime, or carbonate of lime, or calcareous earth, may
be the term used in reference to any such manure used, or recom-
mended, the general, most important, and all effects other than
some of the earliest and least certain to occur, are the same in
practice of all. The operation in every case is that of calxing. In
presenting the theory, and in reasoning, and instruction, it is im-
portant to maintain the precise line of separation and distinction
between the artificial product, quick or caustic lime, and the
naturally existing calcareous earth, or carbonate of lime. But in
practical effects they are the same, excepting those only which
may be due to the different early conditions of the different sub-
stances. Therefore, (always allowing for those early and transient
and minor differences), whatever I may say of the operation of
calcareous earth as manure, would as well be produced by the pro-
per use of lime ; and whatever other writers on lime as manure
have correctly stated, even though perhaps designed by them to be
confined to quick-lime, would, as to all abiding and important
effects and operations, apply as well to mild and naturally existing
calcareous earth, in any of its various forms.

Further — even when the first chemical characters of both caustic
lime and carbonate of lime have been altered in the soil, and they
may have become changed to other salts of lime, by combining
with different acids of soils, still, judging from all experienced and
abiding effects, the general and jaeneficial operations of the original
manures still continue. The only known exception is, and which
is abundantly obvious, that the power to neutralize acids has then
been fully used, and cannot again be exercised by the same lime
on any subsequently produced acids. — 1849.]*

[* Recent Confirmation. — Johnston says — " The eifects of pure lime upon
the land, and upon vegetation, are ultimately i\\Q same, whether it be laid on

in a state of hydrate [or newly slaked], or of carbonate."

"In general, however, the chemical action of the marls and calcareous
Bands is precisely the same in kind as that of lime in the burne^ and slaked
state, and so far the effects Avhich Ave have already seen to be produced by
marls, represent also the general effects of lime in any form." — Lectures,
p. 390. And further — " You may safely proceed on the principle that the
lime in the marls, &c., will ultimately produce precisely the same effects

106

FORM OP CLASSIFICATION OP MANURES.

Alimentary, or serving as
food for plants — as

Solvent of alimentary ma-
nures— as

Fixers, or Mordants —
serving to combine with or
set other manures in* soils

Neutralizing acids — as

Mechanical, or improving
by altering the texture of
soil — as

Specific, or furnishing in-
gredients necessary for par-
ticular plants — as

upon your land, as the lime from the kiln, provided you lay on aii equal
quantity, and in an equally minute state of division. The effect ivill only
be a little more slow," &c.— lb. p. 387.— 1849.]

[By adopting the views which have been presented of the action of cal^
careous earth and of lime as manures, and those which are geftefally fe-
ceived as to the modes of operation of other manures, the following table
has been constructed, which may be foimd useful, though necessarily imper-
fect, and in part founded only on conjecture. The various particular kinds
of manures are arranged in the supposed order of their power, under the
several heads or characters to which they belong ; and when one manure
possesses several different modes of action, the comparative force of each is
represented by the letters annexed — the letter a designating its strongest
or most valuable agency, b the next strongest, and so on as to c and d.

PROPOSED CLASSIFICATION OF MANURES.

Feathers, hair, woollen rags.

Pounded bones, (6)

All putrescent animal and vegetable
substances, as dung.

Stable and farm-yard manures, [a)

Straw, {a)

Green crops ploughed in, and dead
grass and weeds left on the sirr-
face. [a)

Quick-lime, (a)

Potash and soap lie, (a)

Wood ashes not drawn, [d)

Paring and burning the surface of the

soil, (a)
' Calcareous earth, including

Lime become mild by exposure, (o)

Chalk, (a)

Lime-stone gravel, {a)

Wood ashes, {b)

Fossil shells (or shell marl), (a)

Marl (a calcareous clay), [a)

Old mortar and lime cements.

All calcareous manures, (i)

Quick-lime, (b)

Potash and soap lie, (6)

Wood ashes, (c)
fClay,

Sand,

Clay marl, (b)

Fermenting vegetable manures, (6)

Green manures, {b)

Unfermented litter, (b)
' Sulphate of lime, or gypsum (for clo-
ver).

Gypseous earth (or green-sand earth),
for clover.

Calcareous manures (for clover)

Phosphate of lime (for wheat) iu

13ones, (a) and

Drawn ashes, {a)
^ Salt, for asparagus, (a). — 18S5.3

CHAPTER X.

INTRODUCTORY AND GENERAL OBSERVATIONS ON MARL
AND LIME.*

Proposition 5. — Calcareous manures will give to our worst soils
a iwwer of retaining putrescent manures^ equal to that of the
hest — and will cause more productiveness, and yield more profit^
than any other infiprovement practicable in lower Virginia.

The theory of the constitution of fertile and barren soils, has
now been regularly discussed. It remains to show its practical
application, in the use of calcareous earth as a manure. If the
opinions which have been maintained are unsound, the attempt to
reduce them to practice will surely expose their futility ; and if
they pass through that trial, agreeing with and confirmed by facts,
their truth and value must stand on impregnable ground. The
belief in the most important of these opinions (the incapacity
of poor soils for improvement, and its cause) first directed the
commencement of my use of calcareous manures ; and the manner
of my practice has also been directed entirely by the views which
have been exhibited. Yet in every respect the results of practice
have sustained the theory of the action of calcareous manures;
unless indeed there be claimed as exceptions the injuries which
have been caused by applying too heavy dressings to poor and acid
lands ; and also the beneficial effects of proper practice being found
to exceed in degree what the theory seemed to promise.

My use of calcareous earth as manure has been almost entirely
confined to that form of it which is so abundant in the neighbour-
hood of our tide-waters — the beds of fossil shells, together with the
matrix, or earth with which they are found mixed. The shells
are in various states — in some beds generally whole, and in others

[* My views of the theory of fertilization have Ibeen presented in the pre-
ceding pages, (chapters ii. to ix. inclusive), precisely as they appeared in
1832 (and, in substance, at a still earlier time), the later additions being
all distinctly marked as such. This was deemed necessary to the main-
tenance of my claim of priority or of originality of opinions, some of
which, though then novel and unsupported by other authority, have since
been recognised as true, and are now generally if not universally received
by writers on agricultural chemistry. The like necessity will not apply to
the remainder of this work ; and therefore the distinguishing of later
additions to or alterations of the edition of 1832, will not be regularly
marked for distinction. Still it will be done whenever it may be required
for more clear exposition, or where the later dates of additions are deemed
of any importance to their purport. — 1852.1

108 FOSSIL SHELLS AND MARL.

reduced nearly to a coarse powder. The earth which fills their
vacancies, and serves to make the whole a compact mass, in most
cases is principally silicious sand, and usually contains no putres-
cent or valuable matter, other than the calcareous.* The same
effects, in the main, might be expected from calcareous earth in
any other form, whether chalk, lime-stone gravel, wood ashes, or
lime — though the two last have other qualities besides the calca-
reous. During the short time that lime can remain quick or caustic^
after being applied as manure, it exerts (as before stated) a solvent
power, sometimes beneficial and at others hurtful, which has no
connexion with its subsequent and permanent action as calcareous
earth.

These natural deposits of fossil shells are commonly, but very
improperly, called marl. This misapplied term is particularly ob-
jectionable, because it induces erroneous views of this manure.
Other earthy manures have long been used in Europe under the
name of marl, and numerous publications have described their
general effects, and recommended their use. When the same name
is given here to a different manure, many persons will consider
both operations as similar, and perhaps may refer to English
authorities for the purpose of testing the truth of my opinions,
and the results of my practice. But no two operations called by
the same name can well differ more. The j)rocess which it is my
object to recommend, is calxing, or simply the ap'plication of calca-
reous, earth in any form ivJiatever, to soils wanting that ingredienty
and generally being quite destitute of it ; and the propriety of the
application depends entirely on the knowing that the manure con-
tains calcareous earth, and what proportion, and that the soil con-
tains none. In England, the most scientific agriculturists apply
the term marl correctly to a calcareous clay of peculiar texture.
But many authors, as well as the illiterate cultivators, have used
that name for any smooth soapy clay, which may or may not have
contained, so far as they knew, any proportion whatever of calca-
reous matter. Indeed, in most cases, they have seemed uncon-
scious of the presence as well as of the importance of that ingre-
dient, by their not alluding to it when attempting most carefully to
point out the distinguishing characters by which marl may be known.
Still less have they inquired into the deficiency of calcareous earth
in soils proposed to be marled — but applied any earth which either
science or ignorance may have called marl, to any soils within a

[* From later observati(^n I have formed the opinion that the colouring
matter of blue marls is vegetable extract, chemically combined with the
calcareous matter, of which opinion the grounds will be stated hereafter.
But still the amount of this vegetable admixture is too small to have much
appreciable effect as food for plants ; and, for all practical use, the general
position assumed above may yet be considered as altogether true. — 1842.]

MARL AND MxVRLING IN ENGLAND. 109

convenient distance — and relied upon the subsequent effects to
direct whether the operation should be continued or abandoned.
These remarks more especially apply to the older ■writers; but
even the later authors, of the highest character (as Sinclair and
Young, for example), when telling of the practical use and valua-
ble effects of marl, omit giving the strength of the manure, and
generally even its nature — and in no instance have I found the in-
gredients of the soil stated, so that the reader might learn wJiat
kind of operation really was described, or be enabled to form a
judgment of its propriety. From all this, it follows that though
what is called marling in England may sometimes be (though
very rarely, as I infer) the same chemical operation on the soil
that I am recommending, yet it may also be either a:pplying clay
to sand, or clay to chalk, or true marl to either of those soils, or
to some other soil still more calcareous than the earth applied ;
and the reader will generally be left to guess, in every separate
case, which of all these operations is meant by the term marling.
For these reasons, the practical knowledge to be gathered from all
this mass of written instruction on marling will be far less abund-
ant than the errors and mistakes of the authors, and the consequent
inevitable false deductions by their readers. The recommenda-
tions of marl by English authors, induced me very early to look
to what was here called by the same name, as a means for improve-
ment. But their descriptions of the manure convinced me that
our marl was nothing like theirs, and thus actually deterred me
from using it, until other and original and more correct views in-
structed me that its value did not depend on its having " a soapy
feel,'^ or on any admixture of clay whatever.*

[* The remarks above were wi'itten in 1820, and are mucli less applica-
ble to authors of later date. How well justified my expressions then were,
will fully appear in the Appendix, in the testimony furnished by quotations
of the language and opinions of many authors.

There is no want of precision and clearness in the definitions of marl
given by modern scientific writers. Though even with some of them, there
are still very remarkable misapplications of the terms ; as incorrect, in-
deed, as could be expected from the most ignorant cultivators. Thus the
former geological surveyor of New Jersey habitually applies the name of
marl to the " green-sand" of that country; which remarkable earth is a
soft incoherent crumbly mass of separate grains, neither clayey nor marly
in texture or compactness, nor in the least calcareous in its chemical com-
position. Still more strange than this, is an example found as late as
1849, in the " Second Visit to the United States" of the distinguished
geologist Sir Charles Lyell. This author says, when passing from New
York to Philadelphia, *' In New Jersey we passed over a gently undulating
surface of country, formed of red marl and sand-stone, resembling in appear-
ance, and of about the same geological age as the new red sand-stone
(trias) of England." Vol. i. p. 191. This error was not caused by
DCierely the careless use of an incorrect provincial term ; for the "new red

10

110 THE NAME OP MARL MISAPPLIED.

[Nevertheless, mucli valuable information may be obtained from
these same English works, on calcareous manure, or on marl (in the

Band-stone" formation of England is largely composed of a true (calcare-
ous) "red marl." Tlie soil in question was probably a red clay, but, as I
Bhould suppose, containing not a particle of calcareous earth — and cer-
tainly having no quality in common with any marl, true or false, or agree-
ing with any of the different understandings of what marl is, in texture or
composition.

According to scientific definition, marl is composed of carbonate of lime
and fine clay. When taken moist from its bed, such marl is not ductile or
plastic, like ordinary clay ; and is broken more easily than bent. It is
cut by a knife to a smooth surface, having an unctuous or soapy feel. When
a lump has been dried, and is then put into water, it speedily crumbles to
powder, or into thin laminre. Puvis (in his " Ussai sur la Marne"), con-
siders the clay and carbonate of lime in marl to be chemically combined —
which opinion seems well founded. He also supposes marl to be generally,
if not universally, of fresh-water formation — as shown by the shells con-
tained.

The term marl may be considered as understood in four principal signi-
fications, and two of these running into numerous provincial varieties.
With all the precision and care in defining that can be used, it will not be
possible for me to avoid using the term sometimes in the different senses in
which it is used by other authorities to whom I may refer, or whose opinions
may be quoted. Therefore, it will serve for better understanding and
greater clearness, to state, in general terms, all the different meanings ap-
plied to the term marl, by different classes.

1. The definition of marl by mineralogists, and men of science, is the
most exact and most restricted in application — a calcareous clay of pecu-
liar texture and physical qualities, as described more at full above, and
elsewhere in this work.

2. The most extended sense — in which I shall use it in reference to its
fertilizing operation, (calxing), to embrace every kind of substance of earthy
texture, containing carbonate of lime in useful quantity to serve as manure,
and that being the principal manuring ingredient.

3. The sense in which it is understood by modern British agricultural
authors — which is the mineralogical marl, but also embraces other earths
used for the calcareous contents.

4. All the provincial applications of the term in different regions — as to
fine clay (in England) — fossil shells, in lower Virginia — calcareous tufa,
or travertine, in our mountain region — and non-calcareous green-sand,
in New Jersey, &c. : In short, to any kind of earth that experience has
proved, or that ignorance has supposed, to be useful as manure.

The operation called "marling" in England is even less like what is
known by the same name here, than are the different substances used un-
der that name. That which I have done, and advise, and call marling (in
conformity to our provincial and incorrect name given to the substance
used), is, as above stated, the application of calcareous earth of any kind,
or from any source, to soils deficient in that ingredient — and also, in quan-
tities no greater than will serve to produce the desired chemical change in
each particular soil. This required proportion of carbonate of lime is
rarely more than will make one per cent, of the soil for its ploughed depth ;
and generally less than half that quantity is enough for profit and for
safety. Hence, according to the strength of the manure and the condi-
tion of the soil, the usual applications lie between the extremes of 100 and

MARLING IN ENGLAND. ' 111

sense in wliicli that term is used among us) — but under a different
head, viz., lime. This manure is generally treated of with as little

500 bushels to the acre — and more generally between 200 and 300. In
England, (even where we know that the manure is truly marl, or is calca-
reous), the quantities applied are enormous, and must act mechanically for
much the greater part, even if acting chemically at all. For there can
be no chemical action, if the soil was calcareous in the slightest degree
before the application. The expense there is great, because of the heavy
applications ; and liming, though that also is there very much heavier and
therefore more expensive than with us, is always deemed cheaper labour,
and is substituted for marling whenever water-borne lime can be obtained.
The case here is reversed — marling being always much cheaper than the
cheapest liming, if the marl is dug on or near to the farm to which it is
applied.

I will cite a few facts and authorities to show the enormous quantities
in which marl is applied in Britain. Arthur Young (in his Farmer's
Calendar, 10th London collection, p. 40), describes and commends the
labours of Mr. Rodwell, who put 140,000 loads of marl (effervescing with
acids), to 120 acres of leased land, with great profit. The size of the load
not stated. But if 20 bushels, this would be (171 loads of 20 bush.) 3420
bushels to the acre. Sir John Sinclair says the red marl (which is calca-
reous, certainly, as I learn from the Agricultural Report of Lancashire)
is the great source of fertilization in Lancashire and Chesliire. " The
quantity used is enormous ; in many cases 300 middling cart-loads to the
acre, and the fields are sometimes so thickly covered as to have the ap-
pearance of a red-soiled fallow, fresh ploughed." (Code of Agriculture.)
Counting these loads at 20 bushels, makes 6000 bushels to the acre. The
Lancashire Report, made by order of the Board of Agriculture, says that
the carts for marling are usually drawn by 3 horses, and carry about 15
cwt. (1680 lbs.) This is a very light load, for short distances and level
ground. This Report gives sundry facts concurring with the foregoing.
A few only will be here quoted. *' The quantity [of marl] laid on is from
2 to 3|^ cubic roods of 64 [cubic] yards to the statute acre; the expense
of which is, according to the distance carried, if within 00 rods [330
yards] on the average, about £8 [or nearly $40] the acre." — "A cubic
rood of marl, of 64 [cubic] yards to the rood, adds nearly half an inch to
the staple of the soil to a statute acre of land." — Consequently, the usual
dressing, of 2 to 3} such "cubic" roods, must give a coat of from nearly
1 inch to nearly If inches to the soil. A particular piece of 9 acres of "a
wretched black sandy waste" (which however was bought for £33 65. M.
per acre), was afterwards marled '< at nearly 12 roods, of 64 cubic yards
to the acre 0/8 rods." [This is a provincial measure, equal to 2 acres, and
18^ perches, statute measure.] This was equal to 20,730 cubic feet to the
[large] acre — and more than as many heaped bushels, if the cubic measure
of the marl was made in its bed. The cost of this marling was £27 l^s.
6d. per [large] acre — [or about $135, or not quite half this quantity and
price, per statute acre]. In this same report, particular estimates are
made of the expenses of marling, at stated rates and distances, Avhich of
course we must suppose ordinary cases. 1. A field of 30 rods square
(about 6 statute acres), marled from a pit in the centre, at 6 cubic roods,
would cost for cartage per rood, 18s., or £32 85. for the 6 acres. 2. If a like
square, adjoining the first, be marled from the same pit, the previous
average distance of 15 rods will be increased by 30, or to 45 rods ( X 5|
yards = 247 yds.), the increased expense will be 12*. the acre, or £54 ia

112 MARLING! IN ENGLAND. LIMING.

clearness or correctness, as is done witli marl; but the reader at
least cannot be mistaken in this, that the ultimate effect of every
application of lime must be to make the soil more calcareous ; and
to that cause solely are to be imputed all the long-continued bene-
ficial consequences, and great profits, which have been derived
from liming. But excepting this one point, in which we cannot
be misled by ignorance or want of precision, the mass of writings
on lime, as well as on calcareous manures in general, will need
much sifting to yield instruction. The opinions published on t>he
mode of operation of lime are so many, so various, and so contra-
dictory, that it seems as if each author had hazarded a guess, and
added it to a compilation of those of all who had preceded him.
For a reader of these publications to be able to reject all that is
erroneous in reasoning, and in statements of facts — or inapplicable
on account of difference of soil, or other circumstances — and thus

all for marling the 6 acres. 3. Another 6 acres, adjoining the last, at 75
rods average distance from the pit, would cost £79 4^. So that at this very
small distance of 412 yards only, and on even, firm, and level ground, the
cost of ordinary marling is about $35 the English statute acre. Of course,
for one or more miles, the expense would be intolerable.

Neither is this marl (or even the poorer "clay" as there termed) in
Lancashire wanting in calcareous matter. Of 4 specimens stated, the
calcareous proportions were between 19J and 22 per cent. I infer, from
general notices, that others are much richer. There is no intimation in
the report as to whether the soils are or are not calcareous before being
marled. But there is other and better authority for supposing that the
soils are naturally calcareous. The red marl of Lancashire is of the
"new red sand-stone" geological formation, and so I presume is the
over-lying soil (Morton on Soils, p. 67). If so, this would remove all
chemical action from the very heavy dressings of calcareous marl in
Lancashire. At p. 70, the same author speaks of the great improvement
made by liming "on the red marl" in Somerset and Devonshire. The de-
servedly high authority of this writer is enough to establish these facts
of improvement which he asserts. But it requires no argument to prove
that when lime is found a beneficial application to a "red marl" soil, or
any soil before calcareous, that it must be by some other mode than that
chemical action which I call marling or calxing, and which always consists
in rendering a soil calcareous, which was not so before. We might safely
infer that the fai'mers of Lancashire do not incur the enormous expense
of their marlings merely to put the calcareous ingredient on their lands.
But the author of the "Report" leaves no doubt on that point. He says:
"Undoubtedly the calcareous matter contained in either marl [the clay or
the richer marl] is of the highest importance ; but obviating the natural de-
ficiencies of the soil, by adding sand to clay, or clay to sand, is of more conse-
quence than the mere calcareous stimulus, which might be obtained at a much
lighter expense" — [i. e. by using lime instead.]

In the appendix there will be presented many more facts in confirmation.
But these alone will go far to prove that the marling of England is still
more different from the "marling" or calxing which I have recommended
and practised, than is our "marl" from the substances so called in Europe.
—1851.]

LIMING. US'*

obtain only what is true, and useful — it would be necessary for him
first to understand the subject better than most of those whose
opinions he was studying. Indeed it was not possible for them to
be correct, when treating (as most writers do) of lime as one kind
of manure, and every diiferent form of the carbonate of lime as so
many others. Only one distinction of this kind (as to mode of
operation and effects) should be made, and never lost sight of —
and that is one of substance, still more than of name. Pure or
quick-lime, and carbonate of lime, are manures entirely different in
their powers and effects. But it should be remembered that the
substance that was pure lime when just burned, often becomes
carbonate of lime before it is used (by absorbing carbonic acid
from the atmosphere) ; still more frequently before a crop is
planted ; and probably always before the first crop ripens. Thus,
it should be borne in mind that the manure spoken of as lime is
often at first, and always at a later period, neither more nor less
than calcareous earth ; that lime, which at different periods is two
distinct kinds of manure, is considered in agricultural treatises as
only one ) and to calcareous earth are given as many different
names, all considered to have different values and effects, as there
are different forms and mixtures of the substance presented by
nature. — 1835.] ,

But, however incorrect and inconvenient the term marl may be,
custom has too strongly fixed its application for any proposed
change to be adopted. Therefore, I must submit to use the word
marl to mean beds of fossil shells, notwithstanding my protest
against the property of its being so applied.*

[* The geological character of this tide-water region renders impossible
the existence of true marl beds, which can only be souglit for Avith hope,
if anywhere in Virginia, in the valleys of our mountain lime-stone
region — where it would be as much in vain to seek for the fossil shells, so
abundant elsewhere. The latter deposit is the product of the ancient
ocean (during the tertiary formations), of which the bottom, with its beds
of shells, has been subsequently "up-heaved" to the position of dry land.
True marl, when found in considerable quantity, is usually, if not always, a
fresh-water formation ; being produced from the earth torn up and borne
along by rapid rivers and mountain streams, flowing over a chalky or
other highly calcareous country. By such suspension and intermingling,
the heavier sand is first dropped, and the still floating calcareous and
aluminous earths mix and then combine chemically in suitable proportions ;
and when the suspending water becomes nearly still, by reaching a lake
or estuary, the lightest earthy matter is deposited and forms marl. This
natural process continues until the receptacle is filled, and the deposit is
raised above the water. However much it may appear like fine clay in
some respects, true marl is very diff"erent in others. It is not in the least
plastic. If laid in water after drying, it speedily crumbles to small frag-
ments, showing a laminated structure, the result of the manner of its de-
position. Some olays, however, destitute of lime, exhibit this mechanical

10*

"114 REMARKS ON EXPERIMENTS.

The following experiments are reported, either on account of
having been accurately made and carefully observed, or as pre-
senting such results as have been generally obtained on similar
soils, from applications of fossil shells to nearly six hundred acres
of Coggins Point farm (made before 1830). It had been my
habit to make written memoranda of such things ; and the mate-
rial circumstances of these experiments were put in writing at the
time they occurred, or not long after. Somo of the experiments
were, from their commencement, designed to be permanent, and
their results to be measured as long as circumstances might per-
mit. These were made with the utmost care. But generally,
when precise amounts are not stated, the experiments were less
carefully made, and their results reported by guess. Every
measurement stated, of land or of crop, was made in my presence.
The average strength of the different marls used was ascertained
by a sufficient number of analyses; and the quantity applied
was known by measuring some of the loads, and having them
dropped at regular distances. At the risk of being tedious, I shall
state every circumstance supposed to affect the results of the ex-
periments ', and the manner of description, and of reference,
necessary to use, will require a degree of attention that few readers
may be disposed to give, to enable them to derive the full benefit
of these details. But, however disagreeable it may be to give to
them the necessary attention, I will presume to say that these ex-
periments deserve it. They will present practical proofs of what
otherwise would be but uncertain theory — and give to this essay
its principal claim to be considered truly instructive and useful.

When these operations were commenced, I had heard of no
other experiments having been made with fossil shells, except two,
which had been tried long before, and were considered as proving
the manure to be too worthless to be resorted to again.

The earliest of these old experiments was made at Spring Gar-
den, in Surry, about 1775, by Mr. Wm. Short, proprietor of that
estate. The extent marled was eight or ten acres, on poor sandy
land. Nothing is now known of the effects for the first twenty-
five or thirty years, except that they were too inconsiderable to
induce a repetition of the experiment. The system of cultivation
was doubtless as exhausting as usual at that time. Since 1812,
the farm has been under mild and improving management gene-
rally. No care has been taken to observe the progress either of
improvement or exhaustion on the marled piece ; but there is no
doubt that the product has continued for the last fifteen years

structure and character in as marked manner as any true marl. Such
clays, in former times, were not distinguished by farmers, or even agri-
cultural writers, from marl. — 1849.]

EARLIEST TRIALS OP MARL IN VIRGINIA. 115

better than that of the adjacent land. Mr. Francis Ruffin, the
present owner of the farm, believed that the product was not much
increased in favourable seasons j but when the other land suffered
either from too much wet or dry weather, the crop on the marled
land was comparatively but slightly injured. The loose reports
that have been obtained respecting this experiment are at least
conclusive in showing the long duration of the effects produced.

The other old experiment referred to was made at Aberdeen,
Prince George county, in 1803, by Mr. Thomas Cocke. Three
small spots (neither exceeding thirty yards square) of poor land,
kept before and since generally under exhausting culture, were
covered with this manure. He found a very inconsiderable early
improvement, which he thought altogether an inadequate reward
for the labour of applying the marl. The experiment, being
deemed of no value, was but little noticed until after the com-
mencement of my use of the same manure. On examination, the
improvement appeared to have increased greatly on two of the
pieces, but the third was evidently the worse for the application.
For a number of years after making this experiment, Mr. Cocke
Lad considered it as giving full proof of the worthlessness of the
manure. But more correct views of its mode of operation, caused
by my experiments and reasoning, induced him to recommence its
•use ', and no one has met with more success, or produced more
valuable early improvement.

Inexperience, and the total want of any practical guide, caused
my applications, for the first few years, to be frequently injudicious,
particularly as to the quantities laid on. For this reason, these
experiments will show what was actually done, and the eifects
thence derived, and not what better information would have directed
as the most profitable course.

The measurements of corn that will be reported were all made
at the time and place of gathering. The measure used for all ex-
cept very small quantities was a barrel, holding five bushels when
filled level, and which being filled twice with ears of corn, well
shaken to settle them, and heaped, was estimated to make five
bushels of grain ; and the products will be reported in grain, ac-
cording to this estimate. This mode of measurement will best
serve for comparing results ; but in most cases it is far from giving
correctly the actual quantity of dry and sound grain, for the fol-
lowing reasons. The common large soft-grained white corn was
the kind cultivated, which was always cut down for sowing wheat
before the best matured was dry enough to grind, or even to be
stored in the ear for keeping ; and when the ears from the poorest
land were in a state to lose considerably more by shrinking. . Yet,
for fear of some mistake, or mixture of the difi"erent quantities,
occurring if measurements were delayed until the crop was gathered,

116 EXPERIMENTS IN MARLINQ.

these experiments were measured when the land was ploughed for
wheat in October. The subsequent loss from shrinking would of
course be greatest on the corn from the poorest and most backward
land, as the most defective and unripe ears would always be there
found. Besides, every ear, however imperfect or rotten, was in-
cluded in the measurement. For these several reasons, the actual
increase of product on the marled land was always greater than
will appear from the comparison of quantities measured ; and from
the statements of all such early measurements, there ought to be
allowed a deduction, varying from 10 or 15 per cent, on the best
and most forward corn, to 30 or 35 per cent, on the latest and
most defective. Having stated the grounds of this estimate,
practical men can draw such conclusions as their experience may
direct, from the dates and amounts of the actual measurements
that will be reported. Some careful trials of the amount of shrink-
age in particular experiments will be hereafter stated.

No grazing had been permitted on any land from which experi-
ments will be reported, since 1814 (or since being cleared, if in
forest at that time), unless the contrary shall be specially stated.
The cropping had also been mild, during that time, though previ-
ously it was the usual exhausting three-shift and grazing course.

CHAPTER XI.

EXPERIMENTS WITH AND EFFECTS OF CALCAREOUS MANURES ON
ACID SANDY SOILS, NEWLY CLEARED.

Proposition 5 — continued.

As most of the experiments on new land were made on a single
piece of twenty-six acres, a general description or plan of the
whole will enable me to be better understood, as well as to be more
concise, by references being made to the annexed figure. It forms
part of the ridge or high table land lying between James Kiver
and the nearest stream running into Powell's creek. The surface
is nearly level, but slightly undulating. The soil in its natural
state very similar throughout, but the part next to the line B C
somewhat more sandy, and more productive in corn, than the part
next to A D ; and, in like manner, it is lighter along A e, than
nearer to D /. The whole soil, a gray sandy acid loam, not more
than two inches deep at first, resting on a yellowish sandy subsoil,
from one to two feet deep, when it changes to clay. Natural

ON NEWLY CLEARED AND ACID LANDS.

117

growth mostly pin'e — next in quantity, oaks of different kinds — a
little of dogwood and cliinquepin — whortleberry bushes throughout
in plenty. The quality of the soil better than the average of ridge
lands in general, but yet quite poor. Judging from experience
of adjoining grounds and similar soil, this land would have pro-
duced as its early and best crop, and under the best treatment,
about 12 bushels of corn to the acre, well ripened and fully shrunk.
And if thereafter kept under ordinary culture and management,
the products would have gradually and speedily sunk to 5 bushels
to the acre. Being still less suitable to wheat, that crop would
have been scarcely worth being sown on the land in its best natural
state (when the product might be 6 bushels), and certainly not at
all after a few years of the usual downward progress. The effects
of putrescent manures were very transient, as on all such poor lands.

Experiment 1.

The part B C (7 A, about 11 acres, grubbed and the trees cut
down in the winter of 1814-15 — Offered to lie three years with
most of the wood and brush on it. February, 1818, my earliest
application of marl was made on the smaller part B C m Z, about
2^- acres. Marl, containing 33 per cent, of pure calcareous earth,
and the balance silicious sand, except a very small proportion of
clay ; the shelly matter finely divided. Quantity of marl to the
acre, one hundred and twenty-five to two hundred heaped bushels.
The whole space B C ^ 7i coultered, and planted in its first crop of
corn in 1818. This was my earliest experiment of calcareous
manures.

Results. 1818. The corn on the marled land evidently much
better — supposed difference, forty per cent.

1819. In wheat. The difference as great, perhaps more so — ■
particularly to be remarked from the commencement to the end
of the winter^ by the marled part preserving a green colour, while

118 ON NEWLY CLEARED ACID LANDS.

the rcmaiacler was seldom visible from a sliort distance, and in the
spring stood much thinner, from the greater number of plants
killed during the winter. The line of separation very perceptible
throughout both crops.

1820. At rest. During the summer marled 3 G g h, at the rate
of five hundred bushels, without excepting the space before covered,
and a small part of that made as heavy as one thousand bushels,
counting both dressings. The shells now generally coarse — average
strength of the marl, 37 per cent, of calcareous earth. In the
winter after, ploughed three inches deep only, as nearly as could
be ; which however, shallow as it was, made the whole new surface
yellow, by bringing the barren sub-soil of yellow sand to the top.
One of my neighbours, an intelligent and experienced farmer, who
saw the land when in this state, pronounced that I "had ruined
the land for ever, by ploughing and turning the soil too deep.''

Besults continued, 1821. In corn. The whole a remarkable
growth for such a soil. The oldest (and heaviest) marled piece
better than the other, but not enough so to show the dividing line.
The average product of the whole supposed to have been fully
twenty-five bushels of ripe and good corn to the acre.

1822. In wheat — and red clover sowed on all the old marling,
and one or two acres adjoining. A severe drought in June killed
the greater part of the clover, but left it much the thickest on the
oldest marled piece, so as again to show the dividing line, and to
yield, in 1823, two middling crops to the scythe — the first that I
had known obtained from any acid soil, without high improvement
from putrescent manures.

1823. At rest — nothing taken off, except the clover on B C wi I.

1824. In corn — product seemed as before, and its rate may be
inferred from the actual measurements on other parts, which will
be stated in the next experimeat, the whole twenty-six acres being
now cleared, and brought under like cultivation.

Experiment 2.

The part e/n o, cleared and cultivated in corn at the same
times as the preceding — but treated differently in some other
respects. This had been deprived of nearly all its wood, and the
brush burnt, at the time of cutting down — and its first crop of
corn (1818) being very inferior, was not followed by wheat in
1819, because promising too little product to pay for the cost of
the crop. This gave two years of rest before the crop of 1821 —
and five years rest out of six, since the piece had been cut down.
As before stated, the soil rather lighter on the side next to o e,
than nf.

March, 1821. A measured acre near the middle, covered with
six hundred bushels of calcareous sand^ containing 20 per cent

ON NEWLY CLEARED ACID LANDS. 119

of calcareous earth, the upper layer of another body of fossil
shells.

Results. 1821. In corn. October — the four adjoining quarter
acres, marked 1, 2, 3, 4, extending nearly across the piece, two
of them within, and two without the marled part, measured as
follows :

Not marled, No. 1, 6^1 . ., ooi v i, i r

D N 4 5i C ^^^^^S® *^ *"*^ ^^^^ ^^^ bushels of gram.

T) ' XT ■ o' o 1 [■ average 33 J bushels.

The remainder of this piece was marled before sowing wheat in
1821.

1823. At rest.

1824. In com — distance 5| by 31 feet, making 2436 stalks to
the acre. October 11th, measured two quarter acres very nearly,
if not precisely, coinciding with Nos. 2 and 3 in the last measure-
ment. The products now were as follows :

No. 2 brought 7 bushels 31 pecks, ")

or per acre, .... 31.1 [-average 31.2|.
No. 3 brought 8 bushels, . . 32 )

Average in 1821, 33.1

Experiment 3.

The parte/rjr h was cut down in January, 1821, and the land
planted in corn the same year. The coultering and after-tillage
very badly executed, on account of the number of whortleberry
and other roots. As much as was convenient was marled at six
hundred bushels, 37 per cent, and the dressing limited by a straight
line. Distance of corn 5i by 3 J feet — ^2262 stalks to the acre.

Results. 1821. October — on each side of the dividing line, a
piece of twenty-eight by twenty-one corn hills measured as follows :

No. 1, 588 stalks, not marled, 2 bushels, equal to 7 bushels 3
pecks the acre.

No. 2, 588 stalks, marled, 41 bushels, equal to 16 bushels 2 J
pecks the acre.

1822. In wheat, the remainder having been previously marled.

1823. At rest. During the following winter it was covered with
a second dressing of marl at 250 bushels, 45 per cent., making
850 bushels to the acre altogether.

1824. In corn. Two quarter acres, chosen as nearly as possible
on the same spaces that were measured in 1821, produced as follows :

No. 1 made 8 bushels, 2 pecks, or to the acre, 34 bushels.
The same in 1821, before marling, . . 7.31

Increase, 26.0f

120 ON NEW AND ACID LAND.

No. 2 made 7 biislicls, 2^ pecks, or to the acre, 30.2
The same ia 1821, after marling, . . 16. 2^

Increase average, 13.3^

The second dressing of marl, or the larger quantity, had but
little eifect in making the increase of crops greater than in 1821.
The difference was caused mainly by the greater length of time
since the clearing of the land.

1825. The whole twenty-six acres, including the subjects of all
these experiments and observations, were in wheat. The first
marled piece, in Exp. 1, was decidedly the best — and a gradual
decline was to be seen to the latest. I have never measured the
product of wheat from any experiment, on account of the great
trouble and difficulty that would be encountered. Even if the
wheat from small measured spaces could be reaped and secured
separately, during the urgent labours of harvest, it would bo
scarcely possible afterwards to carry the different parcels through
all the operations necessary to show exactly the clean grain derived
from each. But without any separate measurement, all my obser-
vations convince me that the increase of wheat, from marling, was
at least equal to that of corn, during the first two years, and cer-
tainly greater afterwards, in comparison to the product before using
marl.

It was from the heaviest marled part of Exp. 1, that soil was
analyzed to find how much calcareous earth remained in 1826
•(page 78.) Before that time the marl and soil had been well
mixed by ploughing to the depth of five inches. One of the
specimens of this soil then examined consisted of the following
parts — half an inch of the surface, and consequently the undecom-
posed weeds upon it, being excluded.
1000 grains of soil yielded

769 grains of silicious sand moderately fine,
15 finer sand.

784

8 calcareous earth, from the manure applied,

108 finely divided gray clay, vegetable matter, &c.

28 lost in the process.

1000

This part, it has been already stated, was originally somewhat
lighter than the general texture of the remainder of the land.

Experiment 4.
The four acres marked KD n o were cleared in the winter of

j

ON NEW AND ACID LAND. 121

1823-4. The lines p q and r s divide tlie piece nearly into quar-
ters. The end nearest A^ o is lighter, and best for corn, and was
still better for the first crop, owing to nearly all that half having
been accidentally burnt over. After twice coultering, marl and
putrescent manures were applied as follows; and the products
measured, October 11th, the same year.

s q not marled nor manured — ^produced on a quarter acre (No.
4), of soft and badly filled corn,

Bush. P.

3 bushels, or per acre 12.

q r and r p, marled 800 bushels (45 per cent.) by three
measurements of difierent pieces-
Quarter acre (No. 1) 5 bushels, very nearly, or per acre 19.3 J
Eighth (No. 2) 2.3ir r average) . . . 22.2

Eighth (No. 3) 3.1J { 24.1^ j ... 27.

s t manured at 900 to 1100 bushels to the acre, of which,
Quarter acre (No. 5) with rotted corn stalks, from a

winter cow-pen, gave 5.2 ^ ..... 22.2
Eighth (No. 6) with stable manure, 4.1| . . 35.2

Eighth (No. 7) covered with the same heavy dress-

ings of stable manure, and of marl also, gave 4.2 . 36.
jp w, marled at 450 bushels, brought not so good a crop

as the adjoining r j9 at 800.
The distance was 5 J by 3i feet. Two of the quarter acres were
measured by a surveyor's chain (as were four other of the experi-
ments of 1824), and found to vary so little from the distance
counted by corn rows, that the dificrence was not worth notice.

1825. In wheat, the difierent marked pieces seemed to yield in
comparison to each other, proportions not perceptibly difierent from
those of the preceding crop — but the best not equal to any of the
land marled before 1822, as stated in the 1st, 2d, and 3d experi-
ments.

1827. "Wheat on a very rough and imperfect summer fallow.
This was too exhausting a course, (being three grain crops in the
four-shift rotation), but was considered necessary to check the
growth of bushes that had sprung from the roots still living. The
crop was small, as might have been expected from its bad pre-
paration.

1828. Corn — in rows five feet apart, and about three feet of
distance along the rows, the seed being dropped by the step.
Owing to unfavourable weather, and to insects and other vermin,
not more than half of the first planting of this field lived ; and so
much replanting of course caused its product to be much less ma-
tured than usual, on the weaker land. All the part not marled
(and more particularly that manured) was so covered by sorrel, as
to require ten times as much labour in weeding as the marled parts,

11

122

ON NEW AND ACID LAND,

which, as in every other such case, bore no sorrel. October 15th,
gathered and measured the corn from the several spaces, which
were laid off (by the chain) as nearly as could be, on the same
land as in 1824. The products so obtained, together with those
of the previous and subsequent courses of tillage, will be presented
below in a tabular form, for the purpose of being more readily
compared.

[On the wheat succeeding this crop, clover seed was sown, but
very thinly, and irregularly. On the parts not marled, only a few
yards width received seed, which the next year showed the ex-
pected result of scarcely any living clover, and that very mean.
On the marled portions, the growth of clover was of middling
quality. Was not mowed or grazed, but seed gathered by hand
both in 1830 and 1831.]

1832. Again in corn. It was soon evident that much injury was
caused to the marled half q p o n, by the too great quantity ap-
plied. A considerable proportion of the stalks, during their growth,
showed strongly the marks of disease from that cause, and some
were rendered entirely barren. A few stalks only had appeared
hurt by the quantity of marl in 1828. On the lightly marled
piece, w p, and also on ic t, where the heaviest marling was accom-
panied by stable manure, there appeared no sign of injury. The
products of the [three] successive crops were as follows :

>

DESCRIPTION.

PRODUCTS OF GRAIN PER ACRE.

1st course.

2d course.

[3d course.

p

1824.

1828.

1832.

October 11.

October 15.

October 26.

Bush, pecks.

Bush, pecks.

Bush, pecks.

s q

Not marled or manured.

12

21 1

17 U

qrl

Marled at 800 bushels,

19 3J

28 H

28

rp2
rp 3

The same.
The same,

22 2 )

27 /

31 0\

27 3

.^5

Cow-pen manure only, 900

to 1100 bushels.

22 2

25 2

more than s q

St 6

Stable manure only, 900

to 1100 bushels,

35 2

29

28 1

w t 7

Marl and stable manure,

both as above.

3R

33 2

37 3^

lop

Marled at 450 bushels.

Less than r \
P (800) /

Equal to r^

— —

31 3

An accidental omission prevented the measvirement of » t 5,. in 1832.]

[This experiment has been made with much trouble, and every
care bestowed to insure accuracv. Still several causes have ope-
rated to aflfect the correctness of the results, and to prevent the
comparative products showing the true rate of improvement^

ERRORS OP THE EXPEEIMENTS. v 123

either from the marl or the putrescent manure. These caases will
be briefly stated.

1st. The quantity of marl (800 bushels) m q r and r pifi nearly
double the amount that ought to have betjn used; and this error
has not only increased the expense uselessly but has served to pre-
vent the increase of product that would otherwise have taken place.
This loss is proved by the gradual increase, aad *t ^st the greater
product of to p, marled at only 450 bushels.

2d. The comparative superiority of all the marled ground to s
qj not marled, is lessened by this circumstance : most of the large
logs, as well as all the small branches, were burnt upon the land,
when it was cleared in 1824, before the experiment was com-
menced ; and the ashes have durably improved a spot where each
of these large fires was made on s q, but have done no good, and
perhaps have been injurious, to the marled pieces that were made
sufficiently calcareous without the addition of ashes. At least, the
good effect of ashes, on spots, is very evident in s q, and has helped
somewhat to increase all its measured products, and no such benefit
has been visible on the marled parts.

3d. The quantity of putrescent manure applied to s t (900 to
1100 bushels) was much too great both for fair experiment and
profit; and the excess of quantity, together with the imperfectly
rotted state of the stable manure, has given more durability to the
effect, than is to be expected from a more judicious and economical
rate of manuring on such land when not marled. For these several
seasons, it is evident that far more satisfactory results than even
these would have been obtained, especially in the amounts of 7iett
products, if only half as much of either marl or manure had been
applied.

There are other circumstances to be considered, which, if not
attended to, will cause the comparative increase or decrease of pro-
duct in this experiment to be misunderstood. It is well known
that poor land put under tillage immediately after being cleared,
as this was in 1824, will not yield near as much as on the next
succeeding course of crops. This increase, which depends merely
on the effects of time, operates independently of all other means
for improvement that the land may possess ; and its rate, in this
experiment, may be fairly estimated by the increase on the piece
s q from 1824 to 1828. The increase here, where time only acted,
was from 12 to 21 i bushels. But as the corn gathered here was
always much th9 most imperfectly ripened, and would therefore
lose the most by shinking, I will suppose eight bushels to be the
rate of increase from time, and that so much of the product of all
the pieces should be attributed to that cause. Then, to estimate
alone the increased or diminished effects of marl or manure on the

124

ERRORS OF THE EXPERIMENTS.

otter pieces, eight bushels should be deducted from all the dif-
ferent applications, and the estimate will stand thus :

1824.

1828.

q r 1
rp 2
rp 3
s t 5
St 6

B. P.

19 3^

22 2
35 2

B. P.

28 li

31

25
29

B. P.

0 2

1 ^

5 2
14 2

From 800 bushels of marl.
800 *' of marl.

1000
1000

cow-pen manure,
stable manure.

Even the piece covered with both marl and stable manure (w t)
shows according to this estimate a diminished effect equal to 10 i
bushels ] which was owing to the marl not being able to combine
with, and fix, so great a quantity of manure, in addition to the
vegetable matter left by its natural growth of wood. The piece
w p, marled at 450 bushels alone, has shown a steady increase of
product at each return of tillage, and thereby has given evidence
of its being the only improvement made in such manner as both
judgment and economy would have directed.

[After the crop and measurement of 1832, it was inferred that
the separate products of such small spaces could no longer be relied
on, owing to the mixture of the surfaces of adjacent parts, necessa-
rily caused by tillage. -Therefore the previously omitted parts were
marled before the next course of crops came round. — 1842.]

CHAPTEE XII.

EFFECTS OF CALCAREOUS MANURE ON ACID CLAY (OR STIFF) SOILS,
RECENTLY CLEARED.

Proposition 5 — continued.

The two next experiments were made on another field of thirty
acres of very uniform quality, marled and cleared in 1826 and the
succeeding years. The soil is very stiff, close, and intractable un-
der cultivation — seems to contain scarcely any sand — but, in fiict,
about one half of it is composed of silicious sand, which is so fine,
when separated, as to feel like the finest flour. Only a small pro-
portion of the sand is coarser than this state of impalpable powder.
Clayey earth of a dirty pale yellow colour forms nearly all of
its remaining ingredients. Before being cleared of the forest
growth, and ploughed, the soil is not an inch deep ; and all below,

EXPERIMENTS ON NEW AND ACID CLAY LANDS. 125

for many feet^ is apparently composed of tlie like parts of clay
and fine sand. This is decidedly the most worthless kind of soil,
in its natural state, that our district furnishes.* It is better for
wheat than for corn, though its product is contemptible in every-
thing. It is difficult to be made wet, or dry — and therefore suffers
more than other soils from both dry and wet seasons, but espe-
cially from the former. It is almost always either too wet or too
dry for ploughing ; and sometimes it will pass through both states
in two or three clear and warm days. If broken up early in win-
ter, the soil, instead of being pulverized by frost, like most clay
lands, runs together again by freezing and thawing ; and by March,
will have a sleek (though not a very even) crust upon the surface,
quite too hard to plant on without a second ploughing. The
natural growth is principally white and red oaks, a smaller proportion
of pine, and an under-growth of whortleberry bushes throughout.

Experiment 5.

On one side of this field a marked spot of thirty-five yards
square was left out, when the adjoining land was marled at the
rate of five hundred to six hundred bushels (37 per cent.) to the
acre. Paths for the carts were opened through the trees, and the
marl dropped and spread in January, 1826, and the land cleared the
following winter. Most of the wood was carried off for fuel ; the
remaining logs and brush burnt on the ground, as usual, at such
irregular distances as were convenient to the labourers. This part
was perhaps the poorer, because wood had previously been cut here
for fuel ; though only a few trees had been taken, here and there,
each winter, for a long time past.

Results, 1827. Planted in corn the whole recent clearing of
fifteen acres — all marled, except the spot left out for experiment :
broken up late and badly, and worse tilled, as the land was gene-
rally too hard, until the season was too far advanced to save the
crop. The whole crop so small, that it was useless to attempt
to measure the products. The difference would have been only
between a few imperfect ears on the marled ground, and still less
— indeed almost nothing — on that not marled.

1828. Again in corn — as well broken and cultivated as usual
for such land. October 8th — cut down four rows of corn running
through the land not marled, and eight others, alongside on the
marled — all fifty feet in length. The rows had been laid off for
five and a half feet — but were found to vary a few inches — for
which the proper allowance was made, by calculation. The spaces
taken for measurement were caused to be thus small by a part of
the corn having been inadvertently cut down and shocked, just
before. The ears were shelled when gathered ; and the products,
11*

126

ON NEW AND AllD CLAY LANDS.

measured in a vessel wliich held (by trial) 1-80 th of a bushel,
■were as follows :

On land not m^led,

4 rows, average 5 feet, and 50 in length (500 square feet) 13 i
measures, or to the acre 7i bushels.

On adjoining marled land,

4 rows, average 5 feet IJ inches by 50 feet= 512 square feet,
25f measures, or to the acre 13 J bushels.

4 next rows, 5 feet 4^ inches by 50 = 537 square feet, 27^ mea-
sures, or to the acre 14 bushels.

1829. In wheat.

1830. At rest — the weeds, a scanty cover.

1831. In corn. October 20th — measured by the chain equal
spaces, and gathered and measured their products. The corn not
marled was so imperfectly filled, that it was necessary to shell it,
for fairly measuring the quantity. The marled parcels, being of
good ears generally, were measured as usual, by allowing two
heaped measures of ears, for one of grain.

On land not marled,
363 square yards made . • . . . . 3 gallons,
" or to the acre, . . . . . . 5 bushels.

On marled land, close adjoining on one side,
363 square yards made rather more than 6 gallons — to the acre,
10 bushels. 363 square yards on another side, made not quite 8
gallons, or to the acre, 12 bushels.

The piece not marled coincided with that measured in 1828, as
nearly as their diiference of size and shape permitted — as did the
last named marled piece, with the two of 1828. The last crop
was greatly injured by the wettest summer that I have ever known,
which has caused the decrease of product exhibited in this experi-
ment— which will be best seen in this form :

Product of grain to the acre.
1828— October 18. 1831— October 20.
Not marled, . 7 bushels 1 peck. . 5 bushels.

Marled (average), 13 " 3 " . 11 "

Experiment 6.

e

D

|c

A

E

r

B

/

MARLING ON ACID CLAY SOIL. 127

The remainder of the thirty acres was grubbed during the win-
ter of 1826-27 '} marled the next summer at five hundred to six
hundred bushels the acre — marl 40 per cent. A rectangle (A)
11 by 13 poles, was laid off by the chain and compass, and left
without marl. All the surrounding land supposed to be equal in
quality with A — and all level, except on the sides E and B, which
were partly sloping, but not o'^herwise different. The soil suited to
the general description given before ; no material difference known
or suspected between the land on which 5th experiment was made
and this, except that the latter had not been robbed of any wood
for fuel, before clearing. The large trees (or all more than ten
inches through) were belted, and the smaller cut down in the be-
ginning of 1828, and all the land west of the line ef, was planted
in corn. As usual, the tillage bad, and the crop very small. The
remainder lying east of e /, was coultered once ; but, as more labour >
could not be spared, nothing more was done with it until the latter
part of the winter, 1829, when it was broken by two-horse ploughs,
oats sown and covered by trowel ploughs ; then clover sown, and a
wooden-tooth harrow passed over to cover the seed, and to smooth
down, in some measure, the masses of roots and clods.

Results, 1829. The oats produced badly ; but yielded more for
the labour required than corn would have done. The young clover
on the marled land was remarkably good, and covered -the surface
completely. In the unmarled part, A, only two casts through had
been sown, for comparison, as I knew it would be a waste of seed.
This looked as badly as had been expected.

1830. The crop of clover would have been considered excellent
even on good land, and was most remarkable for so poor a soil as
this. The strips sown through A, had but little left alive, and
that scarcely of a size to be observed, except one or two small
tufts, where I supposed some marl had been deposited by the
cleaning of a plough, or that ashes had been left, from burning
the brush. The growth of clover was left undisturbed until after
midsummer, when it was grazed by my small stock of cattle, but
not closely.

1831. Corn on the whole field. October 20th, measured care-
fully half an acre (10 by 8 poles) in A, the same in D, and half
as much (10 by 4) in E. No more space could be taken on this
side, for fear of getting within the injurious influence of the con-
tiguous woods. No measurement was made on the side B, because
a large oak, which the belting had not killed, aficcted its product
considerably. Another accidental circumstance prevented my
being able to know the product of the side C, which however was
evidently and greatly inferior to all the marled land on which oats
and clover had been raised. This side had been in corn, followed
by wheat, and next (1830) under its spontaneous growth of weeds.

128 EFFECTS ON ACID CLAY SOIL.

The corn on each of the measured spaces was cut down, and put
in separate shocks — and on Nov. 25th, when well dried, the parcels
were shucked and measured, before being moved. We had then
been gathering and storing the crop for more than fifteen days ;
and therefore these measurements may be considered as showing
the amount of dry and firm grain, without any unusual deduction
being required for shrinkage.

Bush. Pka.
A (half acre) made 7 J bush, of ears, or of grain to the acre, 7 1

D (half acre) 16| 16 3

E (quarter acre) 11 . . . . . . 22

The sloping surface of the side E, prevented water from lying
on it, and therefore it sufi'ered less, perhaps not at all, from the
extreme wetness of the summer, which evidently injured the growth
on A and D, as well as of all the other level parts of the field.

[1832. The field in wheat.

1833. In clover, which was grazed, though not closely, after it
had reached its full growth.

■ 1834. Corn, a year earlier than would have been permitted by
the four-shift rotation. The tillage was insufiicient, and made still
worse by the commencement of severe drought before the last
ploughing was completed, which was thereby rendered very labori-
ous, and imperfect withal. The drought continued through all
August, and greatly injured the whole crop of corn.

Results continued. October 22d. Marked off by a chain half
an acre within the space A (8 by 10 poles) as much in D, and a
quarter acre (10 by 4 poles) in each of the other three sides C, B,
and E, having each of the last four spaces as near as could be to
the outlines of the space A. The products carefully measured (in
the ears) yielded as follows :

A, not marled, yielded 6 bush. 0^ peck of grain, to the acre.

D, marled, " 19 " 3^ " «

E, do. " 20 " 1 " "
C, do. " 20 " 2 " "

B, do. " 20 " IJ " "

In comparing these products with those of the same land in
1831, stated above, it should be remembered that the corn formerly
measured was dry, while that of the last measurement had yet to-
lose greatly by shrinking. As, after early gathering, the corn from
the poorest land of course will lose most by drying, and as the
ears on A were generally very defective and badly filled, if the
measurement had been made in the sound and well dried grain of
each parcel, the product of A could not have exceeded one-fourth
of that of the surrounding marled land, and probably was less.

But though these differences of product present the improvement .
caused by marling in a striking point of view, this close and stub-

EFFECTS ON ACID CLAY SOIL. 129

bora soil at best is very unfit fof the com crop; and its highest
value is found under clover, and in wheat on clover, of which some
proofs will be found in the next experiment. The first crop of
clover, however, after marling, has not since been equalled. — 1835.]
[My subsequent distant residence prevented my observing this
field when under any matured crop, until in 1842, when in wheat.
The then growth on the unmarled space was certainly not more than
one-fourth as much as that of the surrounding ground. — 1842.]

Experiment 7. , ' '

Another piece of land of twenty-five acres, of soil and qualities
similar to the last described (Exp. 5 and 6), was cleared in 1818,
and about 6 acres marled in 1819, at about three hundred and fifty
bushels. The course of cultivation was as follows :

1820. Corn — benefit from marl very unequal — supposed to vary
between twenty-five and eighty per cent.

1821. Wheat — the benefit derived greater.

1822. At rest.

1823. Ploughed early for corn, but not planted. The whole
marled at the rate of six hundred bushels (40 per cent.), again
ploughed in August, and sown in wheat in October. The old
marled space more lightly covered, so as to make the whole nearly
equal.

1824. The wheat much improved.
1825 and 1826, at rest.

1827. Corn.

1828. In wheat, and sown in clover.

1829. The crop of clover was heavier than any I had ever seen
in this part of the country, except in some very rare cases of rich
natural soil, where gypsum was used and acted well. The growth
was thick, but unequal in height (owing probably to unequal
spreading of the marl), standing from fifteen to twenty-four inches
high. The first growth was mowed for hay, and the second left to
manure the land.

1830. The clover not mowed. Fallowed in August, and sowed
wheat in October, after a second ploughing.

1831. The wheat was excellent, almost heavy enough to be in
danger of lodging. I supposed the product to be certainly twenty
bushels, perhaps twenty-five, to the acre.

As it had not been designed to make any experiment on this
land, the progress of improvement was not observed with much
care. But whatever were the intermediate steps, it is certain that
the land, at first, was as poor as that forming the subjects of the two
preceding experiments in the unimproved state (the measured pro-
ducts of which have been given), and that its last crop was at least
four times as great as could have been obtained, if marl had not

130 EFFECTS ON IMPOVERISHED ACID SOILS.

been applied. The peculiar fitness of this kind of soil for clover
after marling, and the supposed cause of the remarkable heavy first
crop of clover, will require further remarks, and will be again
referred to hereafter.

CHAPTER XIII.

THE EFFECTS OF CALCAREOUS MANURES ON ACID SOILS REDUCED
BY CULTIVATION.

Proposition 5 — continued.

My use of marl has been more extensive on impoverished acid
soils than on all other kinds, and has never failed there to produce
striking improvement. Yet it has unfortunately happened that the
two experiments made on such land with most care, and on which
I relied mainly for evidence of the durable and increasing benefit
from this manure, have had their beneficial effects almost destroyed
by the applications having been made too heavy. These experi-
ments, like the 4th and 6th, already reported, were designed to re-
main without any subsequent alteration, so that the measurement
of their products, once in every succeeding course of crops, might
exhibit the progress of improvement under all the different circum-
stances. As no danger was then feared from such a course, marl
was applied heavily, that no future addition might be required ;
and for this reason, I have to report my greatest disappointments
exactly in those cases where the most evident success and increas-
ing benefits had been expected. However, these failures will be
stated fairly, and as fully as the most successful results ; and they
may at least serve to warn from the danger of error, though not ta
show, as was designed, the greatest profits of judicious marling.

[It should be observed that the general rotation of crops pur-
sued on the farm, on all land not recently cleared, was that of four
shifts (corn, wheat, and then the land two years at rest and not
grazed), though some exceptions to this course may be remarked
in some of the experiments to be stated.]

Experiment 8.

Of a poor sandy acid loam, seven acres were marled at the rate
of only ninety bushels (37 per cent.) to the acre ; laid on and
spread early in 1819.

Results, 1819. In corn — the benefit too small to be generally
perceptible, but could be plainly distinguished along part of tho
outline, by comparing with the part not marled.

EFFECTS ON IMPOVERISHED ACID SOILS. 131

1820. Wheat — the effect something better ; and continued to be
visible on -the weeds following, until the whole was more heavily
mai'led in 1823.

'Experiment 9.

In the same field, on soil as poor and more sandy than 'the last
described, four acres were marled at one hundred and eighty
bushels (37 per cent.), March 1818. A part of the same was also
covered heavily with rotted barn-yard manure, which also extended
through similar land not marled. This furnished for observation,
land marled only — manured only — marled and manured — and some
without either. The whole space, and more adjoining, had been
heavily manured five or six years before by summer cowpens, and
stable litter — of which no appearance remained after two years.

Results, 1819. In corn. The improvement from marl very evi-
dent ; but not to be distinguished on the part covered also by ma-
nure, the effect of the latter so far exceeding that of the marl as
to conceal it.

1820. In wheat. In 1821 and 1822, at rest.

1823. In corn — 5 J by 3i feet. The following measurements
were made on adjoining spaces on October 10th. The shape of the
ground did not admit of larger pieces, equal in all respects, being
measured, as no comparison of products had been contemplated at
first, otherwise than by the eye.

Bush. Quarts.
From the part not marled, 414 corn-hills made 75 quarts — ♦

or per acre, 13 26

Marled only, 414 . . . . 100 . 18 12
Manured only, 490 ... . 105 . 15 5
Marled and manured, 490 . . . 130 . 20 20

The growth on the part both marled and manured was evidently
inferior to that of 1819. This was to be expected, as the small
quantity of calcareous earth was not enough to fix half so much
putrescent manure ] and, of course, the excess was as liable to
waste as if no marl had been used.

Experiment 10.

Twenty acres of sandy loam, on a sandy sub-soil, covered in 1819
with marl of about 30 per cent, average proportion of calcareous
earth, and the remainder silicious sand — at 800 bushels to the acre.
This land had been long cleared, and much exhausted by cultiva-
tion ; since 1814 not grazed, and had been in corn only once in
four years ; and, as it was not worth sowing in wheat, had three
years in each rotation to rest and improve by receiving all its scanty
growth of weeds. The same course has been continued from 1819
to 1832, except that wheat has regularly followed the crops of

132

EFFECTS ON ACID AND SANDY BOILS.

corn, leaving two years of rest in four. This soil was lighter than
the subject of any preceding experiment, except the 9th. On a
high level part, surrounded by land apparently equal, a square of
about an acre (A) was staked off, and left without marl — which
that year's work brought to two sides of the square (C, D, and E).

c

1

...A

2

i)

B

E

Not marled.
Bush,
ere in A, 7

7
7

Half acre

The same in A,

Half acre in B,

Bush.

Pecks.

12

3

13

3f

15

Oi

Results, 1820. In corn. October 13th, three half acres of marled
land were measured, and as many on that not marled, and close ad-
joining, and produced as follows :

Marled.
Pecks.

1 adjoining in C,
1 " D,

2J " E,

The average increase being 12 1 bushels of grain to the acre,
nearly 100 per cent, as measured, and more than 100 if the defect-
ive filling, and less matured state of the corn not marled, be con-
sidered. The whole would have lost more by shrinkage than is
usual from equal products.

1821. The whole in wheat ; much hurt by the wetness of the
season. The marled part more than twice as good as that left out.

1822 and 1823. At rest. A good cover of carrot weeds and
other kinds had succeeded the former growth of poverty grass and
sorrel, and every appearance promised additional increase to the
next cultivated crop. November, 1823, when the next ploughing
was commenced, the soil was found to be evidently deeper, of a
darker colour, and firmer, yet more friable. The two-horse ploughs
with difficulty (increased by the cover of weeds) could cut the re-
quired depth of five inches, and the slice crumbled as it fell from
the mould-board. But as the furrows passed into the part not
marled, an immediate change was seen, and even felt by the
ploughman, as the cutting was so much more easy, that care was
necessary to prevent the plough running too deep ; and the slices
turned over in flakes, smooth and sleek from the mould-board, like
land too wet for ploughing, which however was not the case. The
marling of the field was completed at the same rate (800 bushels),

DISEASE OF CROPS FROM OVER-MARLING.

133

whicli closed a third side (B) of the marked square. The fourth
side was my neighbour's field.

1824. In corn. The newly marled (on B) showed as early and
as great benefit as was found in 1820 on C and J); but yet was
very inferior to the old, until the latter was 10 or 12 inches high,
when it began to give the first known evidence of the very injuri-
ous effects of using this manure too heavily. The disease thus
produced became worse and worse, until many of the plants had
been killed, and still more were so stunted as to leave no hope of
their being otherwise than barren. The effects will be known from
the measurements which were made as nearly as could be on the
same ground as the corresponding marks in 1820, and will be ex-
hibited in the table, together with the products of the succeeding
rotations. Besides the general injury suffered here ih 1824, there
were one hundred and three corn-hills in one of the measured
quarter acres (in C), or more than one-sixth, entirely barren, and
eighty-nine corn-hills in another quarter acre (D). In counting
these, none of the missing hills were included, as these plants
might have perished from other causes. [This unlocked for disaster
diminished the previous increase gained by marliag, by nearly one-
half; and the damage has since been still greater, at each succes-
sive return of cultivation until some years after 1832.

Just before planting the crops of 1832, straw and chaff very
imperfectly rotted by exposure, and which contained no admixture
of animal manure, were applied at the rate of 800 bushels the
acre to half the square without marl (A, 1), and to the adjacent
parts of the marled land. The vegetable manure showed but slight
benefit, until after all the worst effects of excessive marling had
been produced; and the later operation of the manure served
barely to prevent a still farther diminution being exhibited by the
land injured by marl.

g

%

DESCEIPTION.

PRODUCT IN SHELLED CORN PER ACRE.

1st course

2d course

Scl course

4th course

w

1820.

1824.

1828.

1832.

October 13.

October 16.

October 13.

October 19.

Bush. pk.

Bush. pk.

Bush. pk.

Bush, pk.

A

N^ot marled,

14 2

16 1

11 3^

9 3

Al

After manuring,

16 3
not mea-

B

Not marled until 1823,

15 1

28

19 2

sured.

"1

Marled in 1819 — manured
■witlr chaff, &c., in 1832,

f25

\ 27 3|
(30 1

19 2
20
not mea-

15
19
not mea-

18

19 ^
not mea-

sured.

sured.

sured.

12

134 EFFECTS CONTINUED.

The crops of wheat were throughout less injured by the excess
of marl than the corn.

For the crop of 1828, ploughed with three mules to each plough,
from six to seven in>ches deep — seldom turning up any sub-soil
(which was formerly within three inches of the surface), and the
soil appearing still darker and richer than when preparing for the
crops of 1824. The ploughing of the square not marled (A) no-
where exceeded six inches; yet that depth -must have injured the
land, as I can impute to no other cause the remarkable diminution
of product, through four courses of the mild four-shift rotation.
It was evident that a still greater depth of furrow was not hurtful
to the marled land. A strip across the field, in another place, was
in 1828 ploughed eight inches deep for experiment, by the side of
another of four inches, and the corn on the deepest ploughing was
the best. Another strip was trench-ploughed twelve inches deep,
without showing any perceptible difference, either of product or in
the effects of damage from the excess of marl.

This square left without marl was the land previously referred to
(page 44) as showing a diminished product through three succes-
sive courses of the rotation recommended hj the author of ' Arator*
as enriching. Since, another crop has been made and measured,
and found to be still smaller than any previous. To whatever
cause this continued falling of, for 16 years, may be attributed, it
is at least a remarkable contradiction to the doctrine of vegetable
matter serving alone to make poor land rich.

Much trouble has been encountered in attending to this experi-
ment, and much loss of product submitted to, since its commence-
ment, for the purpose of knowing the progress and extent of the
evil caused by the excess of marl. But another portion of the
field, marled as heavily in 1824, and where equal damage was ex-
pected to ensue, has been entirely relieved by intermitting the corn
crop of 1828, sowing clover, which (by manuring with gypseous
earth, or green-sand earth, at 20 bushels to the acre) produced
well, and which was left to fall and rot on the land. The next
growth of corn on this part of the field (1832) was free from dis-
ease, and though irregular, seemed to the eye to amount to full
twenty-five bushels to the acre. — 1835.]

[After 1836, the rotation and management of this field ceased
to be regular or uniform, as previously 3 and also, by cross plough-
ing, &c., during so many years, marl had necessarily become
slightly diffused over the space designed to remain without marl.
Therefore no more measurements were made, as they could no
longer be relied on for accurate comparison. The unmarled part,
even with its slight accidental gain of marl from the surrounding
ground, and half the pi6ce having also been dressed with putres-
cent manure in 1832 (as stated above), is but very little improved

EFFECTS ON ACID SANDY SOILS. 135

since 1820. This and other spots, at first omitted for comparison,
when no longer fit for that purpose, were subsequently marled. —
1849.]

Experiment 11.
The ground on which this experiment was made was in the
midst of nineteen or twenty acres of soil apparently similar in all
respects — level, gray sandy loam, cleared about thirty years before,
and reduced as low by cultivation as such soil could well be. The
land that was marled and measured was about two hundred yards
distant from experiment 2, and both places are supposed to have
been originally similar in all respects. This land had not been culti-
vated since 1815, when it was in corn — but had been once ploughed
since, November 1817, which had prevented broom-grass from
taking possession. The ploughing then was four inches deep, and
in five and a half feet beds, as recommended in 'Arator.' The
growth in the year 1820 presented little except poverty grass
(^Aristida gracilis), running blackberry briers, and sorrel — and the
land seemed very little if at all improved by its five successive
years of rest. A small part of this land was covered with calca-
reous sand (20 per cent.), quantity not observed particularly, but
probably about 600 bushels.

C

1

•A....

2

B

Results. 1821. Ploughed level, and planted in corn — distance
f>h by 3 J feet. The measurement of spaces nearly adjoining,
made in October, was as follows :
23 by 25 corn-hills, not marled (in A) made 2i bushels, '\

or per acre, . . . , , 8| > ^^^-T

23 by 25 corn-hills, marled (on the side B) 5| . 22^ J ^^^^V-

1822. At rest. Marled the whole, except a marked square of
fifty yards, containing the space measured the preceding year.
Marl 45 per cent, and finely divided— 350 bushels to the acre — ■
from the same bed as that used for experiment 4. In August,
ploughed the land, and sowed wheat early in October.

1823. Much injury sustained by the wheat from Hessian fly,
and the growth was not only n^ean, but very irregular ; but it was
supposed that the first marled place (on the side B) was from 50
to 100 per cent, better than the last marled, and the last superior
to the included square not marled (A), in as great a proportion.

• 1824. Again in corn. The eflfects of disease from marling were

136 EFFECTS ON ACID SANDY SOILS.

as injurious here, both on the new and old part, as those described
in experiment 10. No measurement of products made, owing to
my being from home when the corn was cut down for sowing wheat.

1825. The injury from disease less on the wheat than on the
corn of the last year on the latest marling, and none perceptible
on the oldest application. This scourging rotation of three grain
crops in four years was particularly improper on marled land, and
the more so on account of its poverty.

1826. White clover had been sown thickly over forty-five acres,
including this part, on the wheat, in January, 1825. In the spring
of 1826, it formed a beautiful green though low cover on even the
poorest of the marled land. Marked spots, which were so diseased
by over-marling as not to produce a grain of corn or wheat, pro-
duced clover at least as good as other places not injured by that
cause. The square, which had been sown in the same manner, and
on which the plants came up well, had no clover remaining by
April, 1826, except on a few small spots, all of which together
would not have made three feet square. The piece not marled,
white with poverty grass, might be seen, and its outlines traced, at
some distance, by its strong contrast with the surrounding dark
weeds in winter, or the verdant turf of white clover the spring
before.

1827. Still at rest. No grazing allowed on the white clover.

1828. In corn — the land broken in January, five inches deep.
October 14th, made the following measurements :

In the square not marled (A), 105 by 104^ feet (thirty-six square
yards more than a quarter of an acre), made one barrel of ears —

Bushels. Pecks.
Or of grain to the acre . . . . 9 If
The same in 1821 8 IJ

Gain, 1 Oi

Old marling (in B)— 105 by 104^ feet— 2i barrels, 22 2
The same in 1821 22 OJ

Gain, IJ

New marling, 105 by 104J feet, on the side that seemed to be the
most diseased (D), 1^ barrels — or nearly 12 bushels to the acre.

[1832. Again in corn. Since 1826, the mild four-shift rotation
had been regularly adhered to. Ploughed early in winter five
inches deep, and again with two-horse ploughs just before planting,
and after manuring the land above the dotted line D x. The ma-
nure was from the stable yard, the vegetable part of it composed
of straw, corn-stalks, corn-cobs, and leaves raked from wood-land,
had been heaped in a wet state a short time before, and was stiU

EFFECTS WITH PUTRESCENT MANURE.

137

hot from its fermentation when carrying to the field. It was then
about half rotted. The rate at which it was applied was about
807 heaped bushels to the acre, which was too heavy for the best
nett profit. The corn on the oldest marling (B) showed scarcely a
trace of remaining damage, while that on I) 2 (not manured) was
again much injured. On the manured part, D 1, and C, the
symptoms of disease began also to show early; but were so soon
checked by the operation of the putrescent manure, that very little
(if any) loss could have been sustained from that cause. The
following table exhibits all the measured products for comparison ;

>

DESCRIPTION.

PRODUCT IN GRAIN, PER ACRE. j

1st course

2cl course

3d course

4th course

1821.

1824.

1828.

1832.

October —

October 14.

October 20.

Bush. pk.

None measur-

Bush. pk.

Bush. pk.

A

f Not marled, '\

8 1^

ed, but the

9 If

9 2n

Al

-1 Not marled & ma- y

product of B

\

[ nured in 1832, J

much reduced

the same

23 3 J

C

Marled in 1822, and

by excess of

manured in 1832,

marl, and D

31 IJ

B

Marled in 1821 (lightly)

22 0^

and C equally

22 2

25

D ~

Marled in 1822 (more

injured from

heavily)

the same

12

17 3 )

Dl ■

The same — and manur-

cause.

\

J

ed in 1832,

the same

34 3 J

The products of the spaces A and B, in 1828, were not only
estimated as usual from the measurement of the corn in ears (which
estimated quantities are those in the table), but they were also
shelled on the day when gathered, and the grain then measured,
and again some months after, when it had become thoroughly dry.
Care was taken that there should be no waste of the corn, or other
cause of inaccuracy. The result showed nearly double the loss
from shrinking in the corn not marled, and of course a proportional
greater comparative increase of product in that marled, besides the
increase which appears from the early measurement exhibited in
the table. The grain of A, not marled, when first shelled, mea-
sured a very little more than the quantity fixed by estimate — made
as usual by measurement of the ears, and lost by shrinking 30 per
cent. The marled grain, from B, measured at first above 4 per
cent, more than the estimate, and after shrinking, fell below it so
much as to show the loss to be 16 per cent. The loss from shrink-
ing in this case was greater than usual in both, from the poverty
and consequent backwardness of the part not marled, and the un-
commonly large proportion of replanted and of course late corn on
the whole.
12*

138 EFFECTS WITH PUTRESCENT MANURE.

The two last experiments, as well as the 4th, were especially de-
signed to test the amount of increased product to be obtained from
marling, and to show the regular addition to the first increase,
which the theory promised at each renewal of tillage. As to the
main objects, all the three experiments have proved failures — and
from the same error, that of marling too heavily. Although, for
this reason, the results have shown so much of the injurious
effects, still, taken altogether, the experiments prove, clearly, not
only the great immediate benefit of applying marl, but also its con-
tinued and increasing good effects when applied in proper quantities.
—1835.]

Experiment 12.

On 9 acres of sandy loam, marled in 1819 at 400 bushels (25
per cent.), nearly an acre was manured during the same summer,
by penning cattle. With the expectation of preserving the ma-
nure, double the quantity of marl, or 800 bushels in all, was laid
on that part. The field in corn in 1820 ; in wheat, 1821 ; and at
rest 1822 and 1823.

Results, 1824. In corn, the second rotation after marling. The
efiects of the dung have not much diminished, and that part shows
no damage from the quantity of marl, though the surrounding
corn, marled only half as thickly, gave signs of general, though
very slight injury from that cause.

Experiment 13.

Nearly two acres of loamy sand were covered with barn-yard
manure, and marl (45 per cent.), at the same time, in the spring
of 1822, and the field put in corn the same year, followed by wheat.
The quantity of marl not remembered — but it must have been
heavy (say not less than six hundred bushels to the acre), as it was
put on to fix and retain the manure, and I had then no fear of
damage from heavy dressings.

Result, 1825. Again in corn ; and except on a small spot of
sand almost pure (nearly a " blowing sand," or liable to be drifted
by high winds in dry weather), no signs of disease from over-
marling were seen, then or afterwards.

CHAPTER XIV.

EFFECTS OF CALCAREOUS MANURES ON " FREE LIGHT LAND.''

Proposition 5 — continued.

The soil known in this part of the country by the name of " free
light land" has so peculiar a character that it deserves a particular
notice. It belongs to the slopes and undulating lands, between the
highest ridges and the water-courses, but has nothing of the dura-
bility which slopes of medium fertility sometimes possess. In its
wood-land state it would be called rich, and may remain productive
for a few crops after beiog cleared j but it is rapidly exhausted,
and, when poor, seems as unimprovable by vegetable manures as
the poorest ridge lands. In its virgin state, this soil might be sup-
posed to deserve the name of neutral ; but its productive power is
BO fleeting, and acid growths and qualities so surely follow its ex-
haustion, that it must be inferred that it is truly an acid soil.

Experiment 14.
The subject of this experiment presents soil of this kind with
its peculiar characters unusually well marked. It is a loamy sandy
soil (the sand coarse), on a similar sub-soil of considerable depth.
The surface waving, almost hilly in some parts. The original
growth principally red-oak, hickory, and dogwood, not many pines,
and very little whortleberry. Cut down in 1816, and put in corn
the next year. The crop was supposed to be twenty-five bushels to
the acre. Wheat succeeded, and was still a better crop for so
sandy a soil; making twelve to fifteen bushels, as it appeared
standing. After 18 months of rest, and not grazed, the next corn
crop, of 1820, was evidently and considerably inferior to the first;
and the wheat of 1821 (which however was a very bad crop, from
too wet a season) could not have been more than five bushels to
the acre. In January, 1820, a piece of 1 J acres was limed, at 100
bushels the acre. The lime, being caught by rain before it was
spread, formed small lumps of mortar on the land, and produced
no benefit on the corn of that year, but could be seen slightly in
the wheat of 1821. The land again at rest in 1822 and '23, when
it was marled, at 600 bushels (37 per cent.), without omitting the
limed piece ; and all sowed in wheat that fall. In 1824, the wheat
was found to be improved by the marl, but neither that, nor the
next crop of 1828, was equal to its earliest product of wheat. The
limed part showed injury in 1824, from the quantity of manure,
but none since. The field was now under the regular four-shift

(139)

140 EFFECTS ON " FREE LIGHT LAND/'

rotation, and continued to recover ; but did not surpass its first
crop until 1831, when it brought rather more than thirty bushels
of corn to the acre (estimated by the eye) — being five or six
bushels more than its supposed fii'st crop.

Experiment 15.
Adjoining this piece, six acres of similar soil were grubbed and
the trees belted in August, 1826— marl at 600 to 700 bushels (37
per cent.), spread just before. But few of the trees died until the
summer of 1827. In 1828, planted in corn ; the crop did not ap-
pear heavier than would have been expected if no marl had been
applied; but no part had been left without, for comparison. 1829,
wheat. 1830, at rest. 1831, in corn, and the product supposed to
be near or quite thirty -five bushels, or an increase of thirty-five or
forty per cent, on the first crop. No measurement was made ; but
the product was estimated by comparison with an adjacent piece,
which measured thirty-one bushels, and which seemed to be inferior
to this piece.

The operation of marl on this kind of soil seems to add to the
previous product very slowly, compared with other soils ) but it is
not the less effectual and profitable in fixing and retaining the vege-
table matter accumulated by nature, which otherwise would be
quickly dissipated by cultivation, and lost for ever.

The remarkable sandy and open texture of the soil on which the last
two experiments were tried, will be evident from the following state-
ment of the quantity and coarseness of the silicious sand contained.
1000 grains of this soil, taken in 1826 from the part that had been
both limed and marled, was found to consist of
811 of silicious sand moderately coarse, mixed with a few grains

of coarse shelly matter (the remains of the marl).
158 finely divided earthy matter, part fine sand, as well as clay
and organic matter.
31 loss.

1000

At the same time, from the edge of the adjoining wood-land
which formed the next described experiment, 15, and which had
not then been marled, a specimen of soil was taken from between
the depths of one and three inches — and found to consist of the
following proportions. This spot was believed to be rather lighter
than the other in its natural state.
865 grains of silicious sand, principally coarse,
107 finely divided earthy matter (partly fine sand), &c.

28 loss.

1000

CHAPTER XV.

EFFECTS OF CALCAREOUS MANURES ON EXHAUSTED ACID SOILS,
UNDER THEIR SECOND GROWTH OF TREES.

Proposition 5 — continued.

Not having owned much land under a second growth of pines, I
can only refer to two experiments of this kind. The improvement
in both these cases has been so remarkable, as to induce the belief
that the '^ old fields'' to be found on every farm, which have been
exhausted and turned out of cultivation thirty or forty years, offer
the most profitable subjects for the application of calcareous manures.

Experiment 16.
May 1826. Marled about eight acres of land under its second
growth, by opening paths for the carts ten yards apart. Marl 40
per cent. ; put 500 to 600 bushels to the acre — and spread in the
course of the summer. In August, belted slightly all the pines
that were as much as eight inches through, and cut down or grub-
bed the smaller growth, of which there was very little. The pines
(which were the only trees) stood thick, and were mostly from
eight to twelve inches in diameter — eighteen inches where standing
thin. The land joined experiment 15 on one side ; but this is
level, and on the other side joins ridge wood-land, which soon be-
comes like soil of experiment 1. This piece, in its virgin state,
was probably of a nature between those two soils ; but less like
the ridge soil than the " free light land.'' No information has been
obtained as to the state of this land when its cultivation was
formerly abandoned. The soil (that is, the depth which has since
been turned by the plough) a whitish loamy sand, on a sub-soil of
the same ; in fact, all loas subsoil before the ploughing, except
half an inch or three quarters, on the top, which was principally
composed of rotted pine leaves. Above this thin layer were the
later dropped and unrotted leaves, lying loosely several inches thick.
The pines showed no symptoms of being killed, until the autumn
of 1827, when their leaves began to have a tinge of yellow. To
suit the cultivation with the surrounding land,' this piece was laid
down in wheat for its first crop, in October, 1827. For this pur-
pose, the few logs, the boughs, and grubbed bushes were heaped,
but not burnt ; the seed then sowed on the coat of pine leaves, and
ploughed in by two-horse ploughs, in as slovenly a manner as may
be supposed from the condition of the land : and a wooden-tooth

(141)

142 ON LAND OP SECOND GROWTH.

harrow then passed over, to pull down the heaps of leaves, and
roughest furrows.

Results. The wheat was thin, but otherwise looked well while
young. The surface was very soon again covered by the leaves
dropping from the then dying trees. On April 2d, 1828, most of
the trees were nearly dead, though but few of them entirely. The
wheat was then taller than any in my crop, and, when ripe, was a
surprising growth for such land, and such imperfect tillage.-

1829 and 1830. At rest. Late in the spring of 1830 an acci-
dental fire passed over the land ; but the then growing vegetation
prevented all of the older cover being burnt, though some was
destroyed everywhere.

1831. In corn. The growth excited the admiration of all who
saw it, and no one estimated the product so low as it actually
proved to be. A square of four (two-pole) chains, or four-tenths
of an acre, measured on November 25 th, yielded at the rate of
thirty-one and three-eighths bushels of grain to the acre.

Experiment 17.
In a field of acid sandy loam, long under the usual cultivation,
a piece of five or six acres was covered by a second growth of pines
thirty-nine years old, as supposed from that number of rings being
counted on some of the stumps. The largest trees were eighteen
or twenty inches through. This ground was altogether on the
side of a slope, steep enough to lose soil by washing, and more
than one old shallow gully remained to confirm the belief of the
injury that had been formerly sustained from that cause. These
circumstances, added to all the surrounding land having been con-
tinued under cultivation, made it evident that this piece had been
turned out of cultivation because greatly injured by tillage. It
was again cut down in the winter of 1824-5. Many of the trees
furnished fence-rails and fuel, and the remaining bodies were
heaped and burnt some months after, as well as the large brush.
In August it was marled, supposed at 600 bushels (37 per cent.),
twice coultered in August and September, and sowed in wheat —
the seed covered by trowel ploughs. The leaves and much of the
smaller brush, left on the ground, made the ploughing troublesome
and imperfect. The crop (1826) was remarkably good; and still
better were the crops of corn and wheat in the ensuing rotation,
after two years of rest. On the last crop of wheat (1830) clover
was sown — and mowed for hay in 1831. The growth stood about
eighteen inches high, and never have I seen so heavy a crop on
sandy and acid soil, even from the heaviest dunging, the utmost
care, and the most favourable season. The clover grew well in the
bottoms of the old gullies, which were still plainly to be seen, and
which no means had been used to improve, except such as all the

MARL ON CALCAREOUS AND NEUTRAL SOILS. 143

land had received. Withm two feet of the surfiice the sub-soil of
this land is of red clay^ which probably helped its growth of clover.

CHAPTER XYI.

EFFECTS OF CALCAREOUS MANURES ALONE, OR WITH GYPSUM, ON
CALCAREOUS AND NEUTRAL SOILS.

Proposition 5 — continued.

Reason had taught that applications of calcareous earth alone
to calcareous soils were so manifestly useless, that no more than two
experiments of that kind have been made by me, of which, as ex-
pected, neither had any improving effect that could be noticed, in
the twelve ensuing years during which the experiments were ob-
served.

When calcareous manures have been applied to neutral soils,
whether new or worn, no perceptible and manifest benefit has been
obtained on the first crop. The subsequent improvement has gra-
dually increased, as would be expected from the power of fixing
manures ascribed to calcareous earth. But however satisfactory
these general results were to myself, they are not such as could be
reported in detail, with any advantage to other persons. It is
sufficiently difficult to make fair and accurate experiments where
early and remarkable results are expected. But no cultivJitor of a
farm can bestow enough care, and patient observation, to obtain
true results from experiments that scarcely will show their first
feeble effects in several years after the commencement. On a mere
experimental farm, such things may be possible ; but not where the
main object of the farmer is to reap profit from his general and
varied operations. The effects of changes of season, of crops, of
the mode of tillage — the auxiliary effects of other manures, and
many other circumstances — would serve to defeat any observations
of the progress of a slow improvement, though the ultimate result
of the general practice might be abundantly evident.

Another cause for being unable to state with any precision the
practical benefit of marling neutral soils, arises from the circum-
stance that nearly all the calcareous manure thus applied by me
has been accompanied by a natural admixture of gypsum; and
though I feel confident in ascribing some effects to one, and some
to the other of these two kinds of manure, yet this division of
operation must rest merely on opinion, and cannot be received as
certain by any other than him who makes and carefully observes

144 GYPSEOUS MARL OF COGGINS POINT.

the experiments. Some of these applications will be described,
that other persons may draw their own conclusions from them.

The cause of these manures being applied in conjunction was
this, A singular bed of marl lying under Coggins Point, and the
only one within a convenient distance to most of the neutral soil
of that farm, contains a very small proportion (perhaps about one
per cent.) of gypsum, scattered irregularly through the mass,
seldom visible, though sometimes and very rarely to be met with
in small crystals. The calcareous ingredient, on a general average
carefully made, was found to be 62 per cent. If this manure had
been used before its gypseous quality was discovered, all its effects
would have been ascribed to calcareous earth alone, and the most
erroneous opinions might thence have been formed of its mode of
operation.

What led me to suspect the presence of gypsum, in this bed of
fossil shells, was the circumstance that throughout its whole extent,
of near a mile along the river bank, this bed lies on another earth,
of peculiar character and appearance, and which, in many places,
exhibits gypsum in crystals of various sizes. This earth has evi-
dently once been a bed of fossil shells, like that which still remains
above ; but nothing now is left of the shells, except numerous im-
pressions of their forms. Not the smallest proportion of calcare-
ous earth can be found, and the gypsum into which it must have
been changed (by meeting with sulphuric acid, or sulphuret of
iron) has also disappeared in most places ; and in others, it remains
only in small quantities — say from the smallest perceptible propor-
tion, to fifteen or twenty per cent, of the mixed mass. In some
rare cases, this gypseous earth is sufficiently abundant to be used
profitably as manure, as has been done, by Mr. Thomas Cocke, of
Tarbay, as well as myself. It is found in the greatest quantity,
and also the richest in gypsum, at Evergreen, two miles below City
Point. There the gypsum frequently forms large crystals of varied
and beautiful forms. The distance that this bed of gypseous earth
extends is about seven miles, interrupted only by some bodies of
lower land, apparently of a more recent formation by alluvion.

In the bed of gypseous marl above described, there are regular
layers of a calcareous rock, which was too hard to use profitably for
manure, and which caused the greatest impediment to obtaining
the softer part. This rock contains between eighty-five and ninety
per cent, of pure calcareous earth, besides a little gypsum and
iron. It makes excellent lime for cement, mixed with twice its
bulk of sand, and has been used for part of the brick-work, atod all
the plastering of my present dwelling-house (at Shellbanks), and
for several of my neighbours' houses. The whole body of marl
also contains a minute proportion of some soluble salts, which pos-

GYPSEOUS MARL. 145

sibly may have some influence on tlie operation of tlie substance,
as manure or cement.

ThuSj from the examination of a single body of marl, there have
been obtained not only a rich calcareous manure, but also gypsum,
and a valuable cement. Similar formations may perhaps be
abundant elsewhere, and their value unsuspected, and likely to re-
main useless. This particular body of marl has no outward ap-
pearance of possessing even its calcareous character. It would be
considered, on slight inspection, as a mass of gritty clay, of no
worth whatever.

[The last preceding paragraphs present, as in the previous edi-
tions, my earliest views of this particular bed of marl. Further
information has taught that it is of the eocene, or more ancient
formation ; and that the underlying stratum (which is usually not
at all calcareous), which I formerly named and treated of as " gyp-
seous earth," is what geologists call ^^ green-sand," a term still less
descriptive, and not at all more accurate. A full account of both
of these bodies will be given in the Appendix. — 1842.]

This gypseous marl has been used only on sixty acres, most of
which was neutral soil, and generally, if not universally, with
early as well as permanent benefits. The following experiments
show results more striking than have been usually obtained ; but
all agree in their general character.

Experiment 18.

1819. Across the shelly island numbered 3 in the examinations
of soils (page 60), but where the land was less calcareous, a strip
of three-quarters of an acre was covered with mussel-shell marl, a
deposit on parts of the river banks supposed to have been made by
the aboriginal inhabitants. Adjoining this, through its whole
length, another strip was covered with gypseous marl, 53 per cent.,
at the rate of 250 bushels.

Results. 1819. In corn. Ntf perceptible eifect from the mussel-
shells. The gypseous marling considerably better than on either
^ide of it.

1820. Wheat — less difference.

1821. Grrazed. Natural growth of white clover thickly set on
the gypseous marling, much thinner on the mussel-shells, and still
less of it where no marl had been applied.

The whole field afterwards was put in wheat on summer fallow
every second year, and grazed closely the intervening year : a
course very unfavourable for observing, or permitting to take place,
any effects of gypsum. Nothing more was noted of this experi-
ment until 1825, when cattle were not turned in until the clover
reached its full size. The strip covered with gypseous marl
showed a remarkable superiority over the other marled piece, ag
13

146 GYPSEOUS MARI. ON NEUTRAL SOILS.

well as over the land which was still more calcareous by nature,
and which had produced better in 1820. In several places, the
white clover stood thickly a foot in height.

Experiment 19.

A strip of a quarter acre passing through rich black neutral
loam, covered with gypseous marl at 250 bushels.

Results. 1818. In corn. By July, the marled part seemed the
best by 50 per cent., but afterwards the other land gained on it,
and little or no difference was apparent when the crop was matured,

1819. Wheat — no difference seen.

1820 and 1821. At rest. In the last summer the marled strip
could again be easily traced, by the entire absence of sorrel (which
had been gradually increasing on this land since it had been
secured from grazing), and still more by its very luxuriant growth
of bird-foot clover, which was thrice as good as that on the adjoin-
ing ground.

Experiment 20.

1822. On a body of neutral soil which had been reduced quite
low, but was well raapured in 1819 when last cultivated, gypseous
marl was spread on nine acres, at the rate of 300 bushels. This
terminated on one side at a strip of mussel-shell marl ten yards
wide — its rate not remembered, but it was certainly thicker, in pro-
portion to the calcareous earth contained, than the other, whicji^ I
always avoided laying on heavily, from a mistaken fear of eatising
injury by too much gypsum. The line of division between the
two marls was through a clay loam. The suVsoil was a retentive
clay, which caused the rain water to keep the land very wet through
'the winter, and early part of spring.

Results. 1822. In corn, followed by wheat in 1823 — not particu-
larly noticed, but the benefits must have been very inconsiderable.
All the mussel-shell marling, and four acres of the gypseous,
sowed in red clover, which stood well, but "was severely checked,
and much of it killed, by a drought in June, when the sheltering
wheat was reaped. During the next winter (by neglect) my
horses had frequent access to this piece, and by their trampling in
its wet state must have injured both land and clover. From these
disasters the clover recovered surprisingly; and in 1824, two mow-
ings were obtained, which, though not very heavy, were better than
from any of my previous attempts to raise this grass. In 1825,
the growth was still better, and yielded more to the scythe. This
was the first time that I had seen clover worth mowing on the
third year after sowing ; and had never heard of its being com-
parable to the second year's growth anywhere in the lower country.
The growth on the mussel-shell marling was very inferior to the

CAUSE OP THE NON-ACTION OF GYPSUM. 147

other, and was not mowed at all the last year, being thin and low,
and almost eaten out by wire-grass ( Cynodon dactylon).

1826. In corn — and it was remarkable that the difference shown
the last year was reversed, the mussel-shell marling now having
much the best crop.

In these and other applications to neutral soils, I ascribe the
earliest effects entirely to gypsum, as well as the peculiar benefit
shown to clover, throughout. The later effects, and especially on

grain

are due to the calcareous earth in the manure.

CHAPTER XYII.

DIGRESSION TO THE THEORY OF THE ACTION OP GYPSUM AS MA-
NURE. SUPPOSED CAUSE OP ITS WANT OP POWER AND VALUE
ON ACID SOILS.

Proposition 5 — continued.

Another opinion was formed from the effects of gjrpseous marl,
as stated in the foregoing chapter, which may lead to profits much
more important than any to be derived from the limited use of this,
or any similar mineral compound — viz. : that gypsum may he pro"
Jitahly used after calcareous manures, on soils on which it was
totally inefficient before. I do not present this as a fact fully esta-
blished, or, even if established, of universal application ; for the
results of some of my own experiments are directly in opposition.
But, however it may be opposed by some facts, the greater weight
of evidence, furnished by my experiments and observations, de-
cidedly supports this opinion. If correct, its importance to our
low country is inferior only to the value of calcareous manures
alone — which value may be almost doubled, if the land is thereby
fitted to receive the wonderful benefits of gypsum on clover.

It is well known that gypsum has failed entirely as a manure on
nearly all the land on which it has been tried in our tide-water
district; and we may learn from various publications, that as little
general success has been met with along the Atlantic coast, as far
north as Long Island. To account for this general failure of a
manure so efiicacious elsewhere, some one offered a reason, which
was received without examination, and which is still considered by
many as sufficient, viz. : that the influence of salt vapours destroyed
the power of gypsum on and near the sea-coast. But the same
general worthlessness of that manure extends one hundred miles
higher than the salt water of th^ rivers, and the lands where it is

148 NON-ACTION OF GYPSUM ON ACID SOILS.

profitably used are mucli more exposed to sea air. Sucli are the
ricli neutral soils of Curie's Neck, Shirley, Berkley, Westover,
Brandon, and Sandy Point, on James river, on all which gypsum
on clover has been extensively and profitably used, in advance of
marling or liming. On acid soils, I have never heard of enough
benefit being obtained from gypsum to induce the cultivator to ex-
tend its use further than making a few small experiments. When
any efi"ect has been produced on an acid soil (so far as known from
my own experience, or the information of others), it has been
caused by applying to small spaces comparatively large quantities ;
and even then, the effects were neither considerable, durable, nor
profitable. Such have been the results of many small experiments
made on my own acid soils — and very rarely was the least percepti-
ble eff'ect produced. Yet on some of the same soils, after marling,
the most evident benefits have been obtained from gypsum on
clover. The soils on which the 1st and 10th experiments were
made (at some distance from these experiments) had both been
tried with gypsum, and at different rates of thickness, before marl-
ing, without the least eff'ect. Several years after both had been
marled, gypseous earth (from the bed referred to, page 144) was
spread at twenty bushels the acre (which gave four bushels of pure
gypsum*) on clover, and produced in some parts a growth 1 have
never seen surpassed. It is proper to state that such results have
been produced only by heavy dressings. Mr. Thomas Cocke, of
Tarbay, in the spring of 1831 sowed nearly four tons of Nova
Scotia gypsum on clover on marled land, the field being a continua-
tion of the same ridge that my 1st, 2d, 3d, and 4th experiments
were made on, and very similar soil. His dressing, at a bushel to
the acre, before the summer had passed, produced evident benefit,
where it is absolutely certain, from abundant previous experience,
that none could have been obtained before marling.

On soils naturally calcareous, I have in some experiments greatly
promoted the growth of corn by gypsum, and have doubled the
growth of clover on my best land of that kind. When the marl
containing gypsum was applied, benefit from that ingredient was
almost certain to be obtained.

All these facts, if presented alone, would seem to prove clearly
the correctness of the opinion, that the acidity of most of our soils
caused the inefficacy of gypsum, and that the application of calca-
reous earth, which will remove the acid, will also serve to bring
gypsum into useful operation. But this most desirable conclusion
is opposed by the results of other experiments, which, though
fewer in number, are as strong as any of the facts which favour that

* There was very little of the gypseous earth so rich as this limited
layer — which was soon all removed for use.

NON-ACTION or GYPSUM ON ACID SOILS. 149

conclusion. If the subject were properly investigated, these facts,
apparently in opposition, might be explained so as no longer to
contradict this opinion, or perhaps might help to confirm it. Good
reasons, deduced from established chemical truths, may be offered
to explain why the acidity of our soils should prevent the operation
of gypsum ; though it may be deemed premature to attempt the
explanation of any supposed fact, before every doubt of the
existence of the fact itself has been first removed.

One of the circumstances will be mentioned, which appears at
first glance most strongly opposed to the opinion which has been
advanced. On the poor acid clay soil, of such peculiar and base
qualities, which forms the subject of the 5th, 6th, and 7th experi-
ments, gypsum has been sufficiently tried, and has not produced
the least benefit, either before marling, or afterwards. Yet the
first growth of clover on this land after marling is fully equal to
what might be expected from the best operation of gypsum. Now
if it could be ascertained that a very small proportion of either
sulphuric acid, or of the sulphate of iron, exists in this soil, it
would completely explain away this opposing fact, and even make
it the strongest support of my position. The sulphate of iron has
sometimes been found in arable soil,* and sulphuric acid has been
detected in certain clays. f I have seen, on the same farm, a bed
of clay of very similar appearance to this soil, which certainly had
once contained one of these substances, as was proved by the form-
ation of crystallized sulphate of lime, where the clay came in con-
tact with a bed of marl. The sulphate of lime was found in the
small fissures of the clay, extending sometimes one or two feet in
perpendicular height from the calcareous earth below. Precisely
the same chemical change would take place in a soil containing
sulphuric acid, or sulphate of iron, as soon as marl is applied. The
sulphuric acid (whether free or combined with iron) would imme-
diately unite with the lime presented, and form gypsum (sulphate
of lime). Proportions of these substances, too small perhaps to be
detected by analysis, would be sufficient to form three or four
bushels of gypsum to the acre — more than enough to produce the
greatest known effect on clover — and to prevent any benefit being
derived from a subsequent application of gypsum ; because there
being already in the soil more gypsum than could act, no additional
quantity could be of the slightest benefit. J

* Davy's Agr. Chem. p. 141. f Kirwan on Manures.

[J Confirmatory testimony. — Johnston has since fully sustained this rea-
Boning, by chemical facts. Besides the sulphate of iron, he names the sul-
phates of alumina and magnesia as occasionally present in soils, and liable
to be hurtful to plants. He adds: "When soils which contain any of the
three salts I have named, have once been limed or marled, it is in vain to

13*

150 GYPSrM MADE ACTIVE ON MARLED LAND.

[Since the publication of the foregoing part of this chapter, in
the edition of 1832, my use of gypsum, on land formerly ^cid, has
been more extended, and the results have been such as to give ad-
ditional confidence in the practice, and, indeed, an assurance of
good profit, on the average of such applications. But still, as be-
fore, disappointments, either total or nearly so, in the effect of such
applications, have sometimes occurred, and without there being
any known or apparent cause to which to attribute such disappoint-
ment in the results.

In 1832, nine acres of the same body of ridge land above re-
ferred to, adjoining the piece on which the 1st, 2d, 3d, and 4th
experiments were made, and more lately cleared, were sown in
clover in the early part of 1831, on wheat. The next spring,
French gypsum was sown at the rate of a bushel to the acre, ex-
cept on four marked adjoining squares, each about one-third of an
acre, one of which was left without gypsum, and the others received
it at the several rates of 2, 3, and 4 bushels to the acre. The
whole brought a middling crop, and was mowed for hay, except the
square left without gypsum, which did not produce more than half
as much as the adjoining land where gypsum was applied at one
bushel the acre. The products of the other pieces were slightly
increased by each addition to the gypsum, but by no means in
proportion to the increased quantity used j nor was the effect of the
four bushels near equal to that formerly obtained, in several cases,
from 20 bushels of gypseous earth taken from the river bank.
Hence it seems that it was not merely the unusual quantity of
gypsum applied in this earth, which produced such remarkable
benefit -, and we must infer that it contains some other quality or
ingredient capable of giving additional improvement to clover.
—1835.]

[Since the first publication of the foregoing passage (In 1835),
and in accordance with the views there presented, more than 10
tons of good French gypsum has been used, in different years and
with less effect, in general, than formerly, in the first few years
after the marling. This general diminution, and more frequent
total failures, may be owing to the longer time that the land has
been marled, and, by the increase of its vegetable supplies serving
as putrescent manure, the land being thereby changed from calca-
reous to neutral, and perhaps in some cases even approaching again
to being acid. If this supposition be well founded, then a repetition
of the marling would not only be profitable in other respects, but

apply gypsum for favouring the clover crop, since the lime, in decomposing
the sulphates, has already formed an abundant supply of this compound
for aU the piu-poses of vegetation." Lectures on Agr. Chem. — p. 414.]

THEORY OF THE NON-ACTION OP GYPSUM. 151

wotild Increase or restore the capacity of the soil to receive benefit
from gypsum. — 1842.]

1832. — The following are my views of the general causes of the
inertness and worthlessness of gypsum as manure, on all acid soils,
and for the different and valuable results from gypsum, after the
soils have been made calcareous.

I do not pretend to explain the mode of operation by which
gypsum produces its almost magical benefits ; it would be equally
hopeless and ridiculous for one ha\'ing so little knowledge of the
successful practice to attempt an explanation, in which so many
good chemists and agriculturists, both scientific and practical, have
completely failed- There is no operation of nature heretofore less
understood, or of which the cause, or agent, seems so totally dispro-
portioned to the effect, as the enormous increase of vegetable
growth from a very small quantity of gypsum, in circumstances
favourable to its action. All other known manures, whatever may
be the nature of their action, require to be applied in quantities very
far exceeding any bulk of crop expected from their use. But one
bushel of gypsum spread over an acre of land fit for its action, may
add more than twenty times its own weight to a single crop
of clover hay.

But without pretending to kccount for the wonderful action of
gypsum as manure, and without entertaining any confidence in any
of the numerous theories heretofore presented, [not excepting the
latest set forth, by Professor Liebig], I concur in the general'
opinion expressed by Davy. This accurate investigator, who took
nothing upon trust which could be subjected to the test of rigid
experiment, pursued that mode to obtain light on this obscure sub-
ject. He found by chemical analysis, that gypsum was always
present in the ashes of red clover, and in quantity, in a good crop,
amounting to three or four bushels to the acre. He inferred that
gypsum, thus always forming a portion of the clover plant, was
essential to its healthy existence ; and that it is necessary to the
structure of the woody fibre of clover and other grasses. But it is
enough if Davy was correct in the main opinion, that a certain
though very small proportion of gypsum is an essential component
part of certain plants, of which the clover tribe furnishes the most
noted examples. If this be so, no matter what may be the office
or function of the gypsum, the small amount necessary for the de-
mands of the plants must he present in the soil, or otherwise the
plants needing it cannot live, or maintain a healthy growth. It will
follow, further, that on soils well adapted for clover in other
respects, but almost totally deficient in gypsum, the application
of so small a dressing as one bushel of that substance to the acre
may enable a full crop of clover to grow, and twice or thrice as
much as the land could have brought without this small application.

152 THEORY OP GYPSUM ON ACID SOILS.

Such I suppose to be tlie circumstances of those lands of this
country on which gypsum exerts the greatest power. But in Eng-
land, though clover culture is universally extended, gypsum has
shown scarcely any benefit as manure, and though extensively
experimented with, has not been found sufficiently operative to be
brought into ordinary practice on any one farm in the kingdom.
This may be accounted for by supposing the soils generally to be
supplied by nature abundantly with gypsum, so that no more is re-
quired. Davy found gypsum in the soil itself of four farms,
examined with this view, and in one of them the very large propor-
tion of nearly one per cent. (^Agricultural Chemistry, Lecture vii.)
But there is another and numerous class of cases in which gypsum
cannot be supposed to be present, and yet when applied shows no
benefit. These are the poor acid soils of lower Virginia (and else-
where), and the cause of which it seems to me not difficult to
explain.

However wonderful and inscrutable the fertilizing power of this
manure may be, and admitting its cause as yet to be hidden, and
entirely beyond our reach, still it is possible to show reasons why
gypsum cannot act in many situations, where all experience has
proved it to be worthless. If this only can be satisfactorily ex-
plained, it will remove much of the uncertainty as to the effects to
be expected ; and the farmer may thence learn on which soils he
may hope for benefit for this manure, on which it will certainly
be thrown away, and by what means the circumstances adverse to
its action may be removed, and its efficacy thereby secured. This
is the explanation that I shall attempt.

If the vegetable acid, which I suppose to exist in what I have
called acid soils, is not in part the oxalic (which is the particular
acid in sorrel), at least, every vegetable acid, being composed of
different proportions of the same three elements, may easily change
to any other, and all to the oxalic acid. This, of all bodies known
by chemists, has the strongest attraction for lime, and will take it
from any other acid which was before combined with it ; and for
that purpose, the oxalic acid will let go any other earth or metal,
which it had before held in combination. Let us then observe
what would be the effect of the known chemical action of these
substances, on their meeting in soils. If oxalic acid were produced
in any soil, its immediate effect would be to unite with its proper
proportion of lime, if enough were in the soil in any combination
whatever. If the lime were in such small quantity as to leave an
excess of oxalic acid, that excess would seize on the other substances
in the soil, in the order of their mutual attractive forces ', and one
or more of such substances are always present, as magnesia, or, more
certainly, iron and alumina. The soil then would not only contain
some proportion of the oxalate of limey, but also the oxalate of either

GYPStJM ON ACID SOILS. 153

one or more of the otlier substances named. Let us now suppose
gypsum to be applied to this soil. The substance (sulphate of lime)
is composed of sulphuric acid and lime. It is applied in a finely
pulverized state, and in quantities from half a bushel to two bushels
the acre — generally not more than one bushel. As soon as the
earth is made wet enough for any chemical decomposition to take
place, the oxalic acid must let go its hase of iron or alumina, and
seize upon and combine with the lime that formed an ingredient
of the gypsum. The sulphuric acid left free, will combine with
the iron, or the alumina of the soil, forming copperas in the one
case, and alum in the other. The gypsum no longer exists —
and surely no more satisfactory reason can be given why no effect
from gypsum should follow. The decomposition of the gypsum has
served to form two or perhaps three other substances. One of them,
oxalate of lime, like all salts of lime, is probable valuable as manure ;
but the very small quantity that could be formed out of one or even
two bushels of gypsum, might have no more visible effect on a
whole acre, than that small quantity of calcareous earth, or farm-
yard manure. The other substance certainly formed, copperas, is
known to be a poison to soil and to plants — and alum, of which the
formation would be doubtful, I believe is also hurtful. In such
small quantities, however, the poison would be as little perceptible
as the manure ; and no apparent effect whatever could follow such
an application of gypsum to an acid soil. So small a proportion of
oxalic axid, or any oxalate other than of lime, would suffice to de-
compose and destroy the gypsum, that it would not amount to one
part in twenty thousand of the soil.

Why gypsum sometimes acts as a manure on acid soils when
applied in large quantities for the space, is equally well explained
by the same theory. If a handful, or even a spoonful of gypsum
is put on a space of six inches square, it would so much exceed in
proportion all the oxalic or other vegetable acid that could speedily
come in contact with it, that all would not be decomposed, and the
part that continued to be gypsum would show its peculiar powers
perhaps long enough to improve one crop. But as tillage served
to scatter these little collections more equally over the whole space
— or even as repeated soaking rains allowed the extension of the
attractive powers- — applications like these would also be' destroyed,
after a very short-lived, limited, and rarely profitable action.

Soils that are naturally calcareous, or even neutral, cannot con-
tain oxalic acid combined with any other base than lime. Hence,
gypsum applied there continues to he gypsum^ and exerts its great
fertilizing power, as in the counties of Loudoun and Frederick.
But even on these most suitable soils, this manure is said not to
be certain and uniform in its effects ; and, of course, more certain
results are not to be looked for with us, I have not undertaken

154 GYPSUM ON ACID SOILS.

to explain its occasional failures any more than its general success,
on the lands where it is profitably used in general — but only why
it cannot act at all, on lands of a different kind.

The same chemical action being supposed, explains why the
power of profiting by gypsum should be immediately awakened on
acid soils after making them calcareous ; and why that manure
should seldom fail, when applied mixed with much larger quantities
of calcareous earth.

[When the foregoing attempt to explain the cause of the non-
action of gypsum on acid soils was written, and first published in 1832
(as it here appears distinguished from the later additions), the dis-
covery of liumic acid by European chemists was not known to me,
and its very general existence in soils, now universally recognised,
was scarcely known to any. Without pretending to identify the
acid of soil whose existence I maintained, as early as 1818, to be
almost universally present and injurious in this country, it is now
clear and unquestioned that the humic acid is thus plentifully and
generally diffused. The effects ascribed above to the supposed
oxalic acid, of decomposing and destroying sulphate of lime when
applied as manure, may be as much produced by the actually pre-
sent humic acid. For, not only is the latter convertible to the
former, as above argued of all vegetable acids, but, without the
need of such conversion, the humic acid is now understood to have
the like power of decomposing sulphate of lime. This is stated
fully and distinctly in a very recent publication (Browne*s Ame-
rican Muck Book, 1852), as follows : "G-ypsuni is decomposed by
carbonate and muriate of barytes, the carbonates of strontia,
potash, soda, and ammonia, as well as by oxalic and liumic acidsy
and where any of the four last named occur naturally in the soil,
or are applied by artificial means, new combinations take place,
which are attended in some cases with beneficial results. . . .
If, however, it [the soil] contains too much free humic acid, it will
decompose the gypsum, so that humate of lime will be formed, and
the sulphuric acid set free, which may then act as a corrosive on the
roots of plants" (p. 71.) Nothing is wanting to the fullest and
clearest establishment of my doctrine as stated above, except that
the humic acid, like the oxalic, has stronger aflSnity for lime than
the sulphuric, and therefore will decompose sulphate of lime
(gypsum), and form instead humate of lime, of which the effect
as manure is altogether different. And that humic acid (or what-
ever may be the acid of soil) really has this stronger affinity for
lime, is sustained by enough agricultural facts within my personal
observation, even if the proposition had uo support whatever from
chemical science. — 1852.J

CHAPTEH XVni.

THE DAMAGE CAUSED BY TOO HEAVY DRESSINGS OF CALCABEOUS
MANURE, AND THE REMEDY.

Proposition 5 — continued.

The injury or disease in grain crops produced by marling has
so lately been presented to our notice, that the collection and com-
parison of many additional facts will be required before its cause
can be satisfactorily explained. But the facts already ascertained
will at least show how to avoid the danger of such injury in future,
and to find remedies for the evils already inflicted by the injudi-
cious use of calcareous manures.

The earliest effect of this kind observed was in May, 1824, on
the field containing experiment 10. The corn on the land marled
four years before sprang up and grew with all the vigour and luxu-
riance that was expected from the appearance of increased fertility
exhibited by the soil, as before described (page 133.) About the
20th of May the change commenced, and the worst symptoms of
the disease were seen by the 11th of June. From having as deep
a colour as young corn shows on the richest and best soils, it be-
came of a pale sickly green. The leaves, when closely examined,
seemed almost transparent, afterwards were marked through their
whole length by streaks of rusty redj separated very regularly by
other streaks of what was then more of yellow than green ; and
next they began to shrivel and die downwards from their extremi-
ties. The growth of many of the plants was nearly stopped.
Still some few showed no sign of injury, and maintained the
vigorous growth which they began with, so as by contrast more
Btrongly to mark the general loss sustained. The appearance of
the field was such, that a stranger would have supposed that he
saw the crop on a rich soil exposed to the worst ravages of some
destructive kind of insects ; but neither on the roots or stalks of
the corn could any thing be found to support that opinion. Before
the first of August this gloomy prospect had somewhat improved.
Most of the plants seemed to have been relieved of the infliction,
and to grow again with renewed vigour. But before that time
many were dead, and it was impossible that the others could so
fully recover as to produce anything approaching a full crop for
the land. It has been shown in the report of the products of Exp.
10, what diminution of crop was then sustained, and that the evil
was not abated in the three succeeding courses of cultivation.

(155)

156 DISEASED CROPS CAUSED BY MARLING.

Still, neither of the diseased measured pieces has fallen quite as
low as its product before marling ; nor do I think that such has
been the result on any one acre together on my farm, though many
smaller spots have been rendered incapable of yielding even so
much as a grain of corn or -wheat.

The injury caused to wheat by marling is not so easy to describe,
though abundantly evident to the observer. Its earliest growth,
like that of corn, is not affected. About the time for heading, the
plants most diseased appear as if they were scorched, and when
ripe will be found very deficient in grain. On very poor spots,
from which nearly all the soil has been washed, sometimes fifty
heads of wheat, taken together, would not furnish as many grains
of wheat. This crop, however, suffers less than corn on the same
land ; perhaps because its growth is nearly completed by the time
that the warm season begins, to which the ill effects of calcareous
manures seem confined. The injury to corn is also greater in a
wet than a drier summer.

When these unpleasant discoveries were first made, two hundred
and fifty acres had already been marled so heavily that the same
evil was to be expected to visit the whole. My labours, thus be-
stowed for years, had been greatly and unnecessarily increased;
and the excess, worse than being thrown away, had served to take
away that increase of crop which lighter marling would have
insured. But though much and general injury was afterwards
sustained from the previous work, yet it was lessened in extent and
degree, and sometimes entirely avoided, by the remedial measures
whigh were adopted. My observation and comparison of all the
facts presented, led to the fallowing conclusions, and pointed out
the course by which to avoid the recurrence of the evil, and the
means to lessen or remove it, where it had already been inflicted.

1st. No injury has been sustained on any soil of my farm by
marling not more heavily than two hundred and fifty heaped
bushels to the acre, with marl of strength not exceeding 40 per
cent, of calcareous earth.

2d. Dressings twice as heavy seldom produce damage to the first
crop on any soil ; and never even on the after crops on ^y calca-
reous, or good neutral soil; nor on any acid soil supplied plenti-
fully with vegetable matter.

3d. On acid soils marled too heavily, the injury is in proportion
to the extent of one or all these circumstances of the soil — poverty,
sandiness, and severe cropping and grazing, whether inflicted pre-
viously or subsequently,

"" 4th. Clover, both red and white, will live and flourish on thi
spots most injured for grain crops by marling too heavily. Thus
in the case before cited of land adjacent to the pieces measured in
experiment 10, and equally over-marled, very heavy red clover was

i

DISEASED CROPS CAUSED BY MARLING. 157

raised in 1830, by adding gypseous earthj and which was succeeded
by a good growth of corn, free from every mark of disease, in 1832.

5th. A good dressing of putrescent manure removes the disease
completely (see Exp. 11, 12, 13). All kinds of marl (or fossil
shells) have sometimes been injurious ; but such effects have been
more generally experienced from the dry yellow 'marl, than from
the blue and wet.

The inferences to be drawn from these facts are obvious. They
direct us to avoid injury by applying marl lightly at first, and to be
still more cautious according to the existence of the circumstances
stated as increasing the tendency of marl to do harm. Next, if
the over-dose has already been given, we should forbid grazing
entirely, and furnish putrescent manure as far as possible ; or omit
one or two grain crops, so as to allow more vegetable matter to be
fixed in the land — apply putrescent manures — and sow clover as
soon as circumstances permit. One or more of these remedies
have been used on most of my too heavily marled land ; and with
considerable, though not always with entire success, because the
means for the cure could not always be furnished at once in suffi-
cient abundance. Other persons, who permitted close grazing, and
adopted a more scourging rotation of crops, have suffered more
damage, from much lighter dressings of marl than those of mine
which were injurious.

But though the unlooked-for damage sustained from this cause
produced much loss and disappointment, and has greatly retarded
the progress of my improvements, it did not suspend my marling,
nor abate my estimate of the value of the manure. If a cover of
500 or 600 bushels was so strong as to injure land of certain
qualities, it seemed to be a fair deduction, that the benefit expected
from so heavy a dressing, might have been obtained from half the
quantity; if not on the first crop, at least on every one after-
wards. That surely is nothing to be lamented. It also afforded
some consolation for the evil' of the too heavy marlings already
applied, that the soil was thereby fitted to seize upon and retain a
greater quantity of vegetable matter, and would thereby ultimately
reach a higher grade of fertility.

The cause of this disease is less apparent than its remedies. It
is certain that it is not produced merely by the quantity of calca-
reous earth in the soil. If it were so, similar effects, shown in
diseased crops, would always be found on soils containing far
greater proportions of that earth. These injurious effects have not
been known, to any extent, except on soils formerly acid, and made
calcareous artificially ; and not on neither neutral or calcareous
soils, even by the addition of a great excess of marl. The small
spots of land that nature has made excessively calcareous, by marl
beds cropping out at the surface of cultivated fields (as the speci-

158 DISEASED CROPS CAUSED BY MARLING.

men 4, page 60), produce indeed a pale feeble growth of corn,
such as might be expected from poor gravelly soils ; but whether
the plants yield grain, or are barren, they show. none of those pecu-
liar and strongly marked symptoms of disease which have been
described. Some such places on my farm, from which great quan-
titles of poor sandy marl had been removed for manure, and where
the remainder still was of unknown depth, have been afterwards
cultivated with the surrounding land ; and with no more aid than
the portion of the adjacent soil carried thereto necessarily by the
plough, these places have gradually improved to a product equal to
12 or 15 bushels of corn per acre, and have never exhibited any
mark of. the marl disease.

By calculation, it appears that the heaviest dressing causing in-
jurious consequences, if mixed to the depth of five inches, has not
given to the soil a proportion of calcareous earth equal to two per
cent. This proportion is greatly exceeded in our best shelly land,
and no such disease is found there, even when the rich mould is
nearly all washed away, and the shells mostly left. [Soils of re^
markable fertility from the prairies of Alabama and Mississippi
have been shown (page 66) to contain from 8 to 16 per cent, of
calcareous earth, all of which proportions were in the state of most
minute division, and therefore most ready to produce this disease,
if it could have been produced by the quantity of this ingredient.
A specimen of soil remarkable for its great fertility, and maintaining
it under 40 years of successive corn culture, in Scioto valley, Ohio,
was sent me by Dr. Thomas Massie. It contained 10 per cent, of
carbonate of lime and magnesia. The soil of the borders of the
Nile*, celebrated for its exuberant fertility through thousands of
successive crops, contains about 25 per cent, of carbonate of lime.
(^LyelVs Geology. y] Very fertile soils in France and England
sometimes contain 20 or 30 per cent. Among the soils of remarka-
ble good qualities analyzed by Davy, one is stated to contain about
28 per cent., and another, which was eight-ninths of silicious sand,
contained nearly 10 per cent, of calcareous earth. Nor does he
intimate that such proportions are very rare. Similar results have
been stated, from analyses reported by Kirwan, Young, Bergman,
and Rozier (page 51) ; and from all the same deduction is inevita-
ble, that much larger natural proportions of calcareous earth, than
our diseased lands have received, are very common in France and
England, without any such effect being produced.

From the numerous facts of which these are exaniples, it is cer^
tain that calcareous earth acting alone, or directly, has not caused
this injury ; and it seems most probable that the cause is some new
combination of lime formed in acid soils only ; and that this new
combination is hurtful to grain under certain circumstances, which

RECAPITULATION. 159

we may avoid, and is liighly beneficial to every kind of clover.
Perhaps it is the [humate, or some other vegetable] salt of limej
formed by the calcareous manure combining with the acid of the
soil, which, not meeting with enough vegetable matter to combine
with and fix in the soil, causes, by its excess, all these injurious
efiects.

CHAPTER XIX.

RECAPITULATION AND MORE FULL STATEMENTS OF THE EFFECTS
OF CALCAREOUS MAJEURES,

Proposition 5 — continued.

From the foregoing experiments may be gathered most of the
eflfects, both injurious and beneficial, to be expected from calcareous
manures, on the several kinds of soils there described. Information
obtained from statements in detail of agricultural experiments is
far more satisfactory, to the attentive and laborious inquirer, than
a mere report of the general opinions of the experimenter, derived
from the results. But however conclusive may be this mode of re-
porting facts, it is necessarily deficient in method, clearness, and
conciseness. It may therefore be useful to bring together the
general results of these experiments in a somewhat digested form,
to serve as rules for practice. Other effects of calcareous m-anurea
will also be stated, which are likewise established by experience,
but which did not belong to any one accurately observed experiment.

The results that have been reported confirm in almost every
particular the chemical powers before attributed to calcareous ma-
nures, by the theory of their action. It is admitted that causes
and effects were not always proportioned, and that sometimes
trivial apparent contradictions were presented. But this is inevi-
table, even with regard to the best established doctrines, and the
most perfect processes in agriculture. There are many practices
universally admitted to be beneficial ; yet there are none of these
which are not found sometimes useless, or hurtful, on account of
some other attendant circumstance, which was not expected, and
perhaps not discovered. Every application of calcareous earth to
a deficient soil is a chemical operation on a great scale. Decompo»
sitions and new combinations are produced, and in a manner gene-
rally conforming to the operator's expectations. But other and
unknown agents may sometimes have a share in the process, and
thus cause unlooked-for results. Such differences between practice
and theory have sometimes occurred iu my use of calcareous ma-

160 RESULTS HAVE CONrORMED TO THEORY.

nures (as may be observed in some of the reported experiments),
but they have neither been frequent, uniform, nor important.

[But in nearly all such cases of disproportion between causes
and effects in the use of marl, the manner of variation has been
in the effects surpassing the anticipated power of the causes (as
previously inferred from reasoning and in advance of any practice),
and in very few, if indeed any cases, of the contrary operation, of
the results falling short of what might have been inferred from the
theory of the action of calcareous manures. For such variation as
this, it may be that no reader will require either excuse or explana-
tion ; nevertheless it is as much due to truth that it should be
stated, as if the opposite kind of difference existed.

Before my earliest trials, or practical knowledge, of the effects
of marl, I was well assured, by my theoretical reasoning, that this
manure would correct the acidity of poor soil, and enable it to be
enriched by putrescent manures. But I was still totally at a loss
to know, or to guess, how much calcareous earth would be required
for that result, or how much time might be required for the suffi-
cient quantity to produce its full effect ; and there were grounds to
fear that the quantity of the manure and time for its operation,
and consequently the cost compared to profit, would be much
greater than after-experience has shown. If 1000 bushels of ordi-
nary marl had been required for an acre, and 10 years' time for that
application to raise the product to double its previous rate, the
theory of the action of calcareous manures would have been sus-
tained. ■ But in fact, as great effect as this has been usually pro-
duced (in judicious and proper practice), by measures of marl and
of time less by three-fourths than those just stated. And thus,
while effects have almost universally exceeded in measure the sup-
posed power of their causes, I may safely assert that in not a sin-
gle case, in the tide-water region, of a judicious application of
marl or lime, has it been known that the effect fell short of what
would be indicated by my theory of the action of calcareous earth
as manure.

But there is still another exception to admit, if it be one, or of
apparent want of accordance between theory and practice; and
unluckily, this case is of the effects falling short of the supposed
power of causes. There has as yet been made but little use of
lime in the region immediately above the granite ridge which forms
the lower falls of our eastern rivers. But almost all the failures
of lime to act that have been heard of, or of effects falling much
short of what were expected and are usual, are among the few ex-
periments which have been made within fifty miles above the
granite ridge. While truth requires that the fact of these failures
should be stated, I pretend not to account for them. It may bo
the case, and probably is, that there is a general difference of

DIFFERENCE OF LANDS. 161

clicmical constitution between lands even of like apparent texture
and qualities, above and below the falls, as there certainly was a
great diflference of geological formation.*

Of the poor lands above the falls, my knowledge is but slight,
and founded only on general and slight personal observation, or the
report and better information of resident cultivators. But judg-
ing from such uncertain lights, I would infer that the lands above
the falls were much less acid than those below, even when as poor.
The growth of pine and of sorrel is more scarce on lands above the
falls ; and gypsum often acts there on natural soils, and lime (in
some knoWn trials) has produced but slight benefit. On the con-
trary, gypsum is scarcely ever operative on any natural soil below
the falls (that is, on any of the great body of acid soil), and lime
never fails to act well on these same lands.

The most important observation to be made on the disproportion
of causes and effects, in the tide-water region, is in regard to good
neutral soils, and especially as to that best class known by the
common name of ^^ chocolate'^ or ^'mulatto land,'' or " hazel loam,''
as designated more properly in England. On such soils, which
constitute the chief value of the best farms of James river, the
applications of lime have been the most extensive, and always
highly effective.

^ The falls of the rivers of eastern Virginia mark the eastern and lower
outline of the primitive region. The soils of that region have been formed
more immediately or recently from the disintegi-ation of rocks ; and this
natilral process is still going on, in the gradual continued disintegration of
the still remaining rocks, and even of gravel and sand. For, however much
the materials of the soils have been intermixed by natural causes, and the
soils thereby made more of uniform character, still each remaining stone,
and even each grain of sand, is a fragment and sample of the original com-
pound rock from which it crumbled down. Most of the different rocks
contain, chemically combined, several, if not all the important chemical
earths; though, as in poor soils, silica and alumina are usually most
abundant, and lime and magnesia are in very minute proportions. Still,
in the intermixture of fragments of all the ordinary rocks of that region,
and by their continued gradual disintegration, there are still furnished to
every soil so formed new supplies of all the necessary earths, and of potash
also. Small as may be the amount of lime and potash, there is some of
each furnished every year to every such soil, by the disintegration of its re-
maining fragments of rocks.

On the other hand, the soils and sub-soils of the region below the falls
are composed of a much eai-lier disintegration of rocks. Except some
rarely found hard pebbles, and gravel (mostly of quartz), all rounded
by being water-rolled, everything in these soils has been reduced to the
minutest particles. Even if these soils had been originally produced from
the same kinds of rocks, as those above the falls, still there must be a
great difference between the soils in which the process of disintegration
and decomposition is yet in continual progress, and those in which it has
been completed and has ceased for countless ages.

14*

162 CALCAREOUS WITH VEGETABLE MATTER.

The fact tliat the effects of calcareous manures so generally ex-
ceed in measure the supposed power and operation of the causes,
and more especially in regard to neutral soils, seemed to indicate
that calcareous manures possessed other fertilizing powers, be-
sides those set forth in Chapter VIII. This, which formerly was
stated as a probability, may now be considered as certain. Evi-
dence of such effects, and of the supposed auxiliary and lately
known causes, will hereafter be presented. Dismissing them from
consideration for the present, I will return to stating the results of
applying marl as they have occurred almost without exception in
my own earlier practice, and which are confirmed by the con-
currence of all known and certain testimony in regard to practical
operations in the marl region of Virginia.]

Under like circumstances in other respects, the benefit derived
from marling will be in proportion to the quantity of vegetable or
other putrescent matter given to the soil. It is essential that the
cultivation should be mild, and that little or no grazing be per-
mitted on poor lands under regular tillage, and which have no
supply of putrescent manure, except the grass and weeds growing
on them while at rest. Wherever farm-yard manure is used, the
land should be marled heavily ; and if the marl is applied first, so
much the better. The marl cannot act by fixing the other manure,
except so far as they are in contact, and when both are well mixed
with the soil.

[When I first asserted the agency and force of calcareous ma-
nures in fixing alimentary manures in soils, and maintained the
great and indispensable^ necessity of that operation, the proposition
was founded almost exclusively on reasoning, and on observation
of natural soils, and not at all on practical effects then experienced
from applications of marl or lime. From the very nature of the
case, such effects as these, however important and valuable, could
not be seen at first, nor fully even in a very few years after begin-
ning to marl, nor their extent be understood and appreciated.
Moreover, my earlier experience had shown so fully the incapacity
of my acid or naturally poor soils to retain alimentary manures,
and my labours and expenditures to apply them had been so very
unprofitable, that I was not myself prepared for the full extent of
the contrary operation, after marl had been applied. And though
the views and estimation of such new operation have been yearly
enlarging, from the experience of practical results, still my esti-
mate of the fixing value of marl fell short of what is now confi-
dently believed, and which is every season manifest, of the greater
effect and permanency, and far greater profit of alimentary ma-
nures, caused solely by the presence of calcareous earth in the
same soils. Notwithstanding that the theory of the action of cal-
. careous manures, as set forth in this essay, and published as early

CALCAREOUS WITH VEGETABLE MATTER. 163

as 1821, made this fixing operation the first of the two most im-
portant agencies, and though that theoretical view guided mj prac-
tice from the beginning, still it was not until after a long time, that
gradually and slowly I fully and truly estimated the full value and
profit of this operation. My early and zealous efi'orts (before be-
ginning to marl) to improve naturally poor lands by the vegetable
and animal manures of the farm, had been so much disappointed,
and the efi*ects had been so inconsiderable as well as so fleeting,
that it was long before I arrived at the conviction of the full ex-
tent of the opposite and new condition of the soil. But during
latter years, the certain and profitable operation, and durable ope-
ration, of every kind of vegetable or alimentary manure, no mat-
ter how or when applied, has been made obvious ; and now my
estimate of value would be, that if marling had no other operation
whatever than this one of making other manures much more active
and durable, the profit from this one source alone would amply re-
ward all the usual labours and expenses of the operation.*]

On "galled" spots, from which all the soil has been washed, and
where no plant can live, the application of marl alone is utterly
useless ; at least, until time and accident shall furnish some addi-
tion of vegetable matter also. Putrescent manures alone would
there have but little efiect, unless in great quantity, and would
soon be all lost. But marl and putrescent matter together serve to
form a new soil, and thus both are brought into useful action ; the
marl is made active, and the putrescent manure permanent. The
only perfect cures that I have been able to make, at one operation,
of galls produced upon a barren sub-soil, were by applying heavy
dressings of both calcareous and putrescent manures together ; and
this method may be relied on as certainly effectual. But though
a fertile soil may thus be created, and fixed durably on galls other-
wise irreclaimable, the cost will generally exceed the vakie of the
land recovered, from the great quantity of putrescent matter re-
quired. Much of our acid hilly land has been deprived, by wash-
ing, of a considerable portion of its natural soil, though not yet
made entirely barren. The foregoing remarks equally apply to
this kind of land, to the extent that its soil has been carried off.
It will be profitable to apply marl to such land ; but its effect will
be diminished, in proportion to the previous removal of the soil.
Calcareous soils, from the difference of texture, are much less apt
to wash than othex kinds. "Within a few years after marling a hilly

[* Confirmatory testimony. — Liming "increases the effect of a given ap-
plication of [putrescent] manure ; calls into action that which, having been
previously added, appears to lie dormant ; and though manure must be
plentifully laid upon the land after it has been well limed, yet the same
degree of productiveness can still be maintained at a less cost of manure
than where no lime has been applied." Johnston's Lectures, p. 391.]

164 MARLINa PREVENTS WASniNG EFFECTS OF RAINS.

field that has been injured by washing, many of the old gulleys
will begin to produce vegetation, and show that a soil is gradually
forming from the dead vegetables brought there by winds and
rahis, although no means had been used to aid this operation.

[This newly acquired ability to resist the washing power of rains,
is one of the most beneficial efi"ects of marling on hilly lands.
And this efi'ect is no less certain, than it is conformable to the
theory of the action of marl and to reason. On soils containing
very little lime (or almost none, as in naked sub-soils), whether
they be sandy or clayey, there is nothing to combine the vegetable
matter with the soil, nor the different ingredients of the soil with
each other. Consequently they have no cohesion, and whenever
made very soft, or semi-fluid by rains, and there is any declivity,
there is nothing to prevent the soil, or upper surface, being washed
off by excessive rain, though falling gently. Of course, torrents
of rain produce the same injurious eff'ects much more rapidly and
effectually. But when such soils have been made calcareous, a
chemical combination and bond of union and coherence is formed
between the lime and the putrescent or organic matter, and of both
with the silicious and argillaceous parts of the soil ; which combi-
nation is able to resist any but an unusual force of the washing
action of rains.* Moreover, by the increase of productive power
thus given, grass grows more kindly and rapidly, and by its decay
the vegetable mould is continually augmented, and thereby the
power of resisting washing is still more increased as the fertility
of the soil is increased. This is but another aspect and operation
of the power of calcareous manure in soils to fix and retain
manures.

The tendency of some very sandy soils to be moved, and in part
blown away, by high winds, is also produced by the want of cohe-
gion of the particles. The wind operates on the soil in its dry
state in the same way, and for the same defect of its constitution,
as does water in rain torrents. The same remedy, calcareous ma-
nure, is even more eff'ectual to prevent the wasting operations of
wind than of water. The absorbent power given to the before
loose and more rapidly drying particles of sandy soils serves to
preserve more moisture at the surface. This alone would tend
much to prevent the moving effect of the wind, which can take
place only on earth nearly or quite dry and pulverulent. Further,
both directly and indirectly (by combining the . organic with the
earthy parts), the calcareous manure, when thoroughly diff"used,
interposes some cohesive particles between the particles of sand.

* Confirmation. — Johnston speaks of organic (or putrescent) matter be-
ing presented to the action of lime " in the state of chemical combination
•with earthy substances — with the alumina, for example, and with lime and
magnesia — already existing in the soil." p. 402.

AND THE BL0WI^X3 AWAY OF SANDS BY WIND. 165

The eiFect in practice is most striking. Fields and farms, which
before were noted for the dense and enormous clouds of dust pass-
ing away from them in every high and drying wind, become free
from such loss in a short time after being marled or well limed.*]

The effect of marling will be much lessened by the soil being
kept under exhausting cultivation. Such were the circumstances
under which we may suppose that marl was tried and abandoned
many years ago, in the case referred to in page 114. Proceeding
upon the false supposition that marl was to enrich by direct action,
like dung, it is most probable that it was applied to some of the
poorest and most exhausted land, for the purpose of giving the
manure wh"at is called a " fair trial." The disappointment of such
ill-founded expectations was a suflGicient reason for the experiment
not being repeated, or being scarcely ever referred to again, unless
as evidence of the worthlessness of marl. Yet with proper views
of the action of this manure, this experiment might at first have
as well proved the early efficacy and value of marl, as it now does
its durability. f

When acid lands are equally poor, the increase of the first crop
from marling will be greater on sandy, than on clay soils ; though
the latter, by heavier dressings and longer time, may ultimately

* I have heard (but do not know from my own personal observation),
that the well-known and valuable farm of Lower Wyanokc, the^property of
the late Fielding Lewis, presented a remarkable example of the frequent
loss of soil by winds, before the liming, and of the cessation afterwards.

On March 1st, 1850, a few days before the writing of these lines, I saw
from the eminence on which my present dwelling stands, a very remarka-
ble exhibition of this conservative power of marl. The night before, there
had fallen a heavy shower ; and also some drizzle after day-break, suc-
ceeded by bright sunshine and a furious wind. Though the rain-water had
stood in puddles in the ruts and low spots of hard roads in the morning,
by 11 o'clock, a. m., dense clouds of dust, rising as high as the tops of the
forest trees on the higher lands, were seen driven off from the light fields
of three different and detached neighbouring farms, and which had not been
marled. A much broader space of surface, intermediate or adjoining, was
also in view, much of which was equally sandy, and fully as much exposed
to the wind. All this land (except one small field, which was both stiff, and
low-lying, and of course not then dry) had been well marled ; and from
none of it was any dust seen to rise. Of the several thousand acres of
arable land in sight, and mostly of sandy soil, all the farms and fields not
marled (and not of clay or wet soil) might have been designated by the
clouds of dust then rising and passing off from them.

■f Confirmation. — "One thing, however, must be borne in mind by those
who, in adopting the best system of [successive] liming, do not wish both
to injure their land and to meet with ultimate disappointment. Organic
matter — in the form of farm-yard manure, or green crops ploughed under,
&c. &c., must be abundantly and systematically added, if at the end of 20
or 40 years the land in which the full supply of lime is kept up is to retain
its original fertility. . . . Otherwise present fertility and gain will be
followed by future barrenness and loss." Johnston's Lectures, p. 386.

166 QUANTITIES OF MARL REQUIRED.

become the best land, at least for wheat and for grass.* The moro
acid the growth of any soil is, or would be, if suffered to remain,
the more increase of crop may be expected from ma^; which is
directly the reverse of the eifects of putrescent manures. The in-
crease of the first crop on my worn acid land, I have never known
under fifty per cent., and more often it is as much as one hundred;
and the improvement continues to increase, under mild tillage, to
three or four times the original product of the land. (See Exp.
11, page 185, and Exp. 4 and 6.) In this, and other general state-
ments of effects, I suppose the land to bear not more than two
grain crops in four years, and not to be subjected to grazing during
tl^e other two ; and that a sufficient cover of marl has been laid on
for use, and not enough to cause disease. It is true, that it is
difficult, if not impossible, to fix that proper medium, varying as it
may on every change of soil, of cropping, and of the kind of marl.
But whatever error may be made in the proportion of marl applied,
let it be on the side of light dressing (except where putrescent
manures are also laid on, or designed to be laid on before the next
course of crops begins) ; and if less increase of crop is gained to
the acre, the cost and labour of marling will be lessened in a still
greater proportion. If, when tillage has served to mix the marl
well with the soil, sorrel should still show to any extent, it will
sufficiently indicate that not enough marl had been applied, and
that it may be added to, safely and profitably. If the nature of the
soil, its condition and treatment, and the strength of the marl, all
were known, it would be easy to direct the amount of a suitable
dressing ; but without knowing these circumstances, it will be
safest to give not more than 200 or 250 bushels of marl, of say 40
per cent, to the acre of worn acid soils. Twice or thrice as much
might be given, safely and profitably, to newly cleared wood-land,
or well manured land. Or, I would advise that the first dressing
should not exceed the quantity which would furnish one per cent,
of carbonate of lime to the soil, for its ploughed depth. If only
3 inches deep, 218 bushels of marl, of 40 per cent,, would furnish
1 per cent, to the soil. Besides avoiding danger, it is more profita-
ble to marl lightly at first on weak lands. If a farmer can carry
out only ten thousand bushels of marl in a year, he will derive
more product, and confer a greater amount of improvement, by
spreading it over forty acres of the land intended for his next
crop, than on twenty ; though the increase to the acre would pro-
bably be greatest in the latter case. By the lighter dressing, the
land of the whole farm will be marled, and be storing up vegetable
matter for its progressive improvement, in half the time that it
could be marled at double the rate.

* Cofifirmation. — "On clay lands more lime is necessary than on light
and sandy soils." Johnston's Lectures, p. 382.

PRESERVING OP VEaETABLE MATTER. 167

The greater part of the calcareous earth applied at one time
cannot begin to act as manure before several years have passed,
owing to the coarse state of many of the shells, and the want of
thoroughly mixing them with the soil. Therefore, if enough marl
is applied to obtain its full effect on the JBrst course of crops, there
will certainly be too much afterwards.

Perhaps the greatest profit to be derived from marling, though
not the most apparent in the first few years, is on such soils as are
full of wasting vegetable matter. Here the effect is mostly pre-
servative, and the benefit and profit may be great, even though the
increase of crop may be very inconsiderable. Putrescent manure
laid on any acid soil, or the natural vegetable cover of those newly
cleared, without marl, would soon be lost, and the crops reduced to
one-half or less. But when marl is previously applied, this waste
of fertility is prevented ; and the estimate of benefit should not
only include the actual increase of crop caused by marling, but as
much more as the amount of the diminution which would otherwise
have followed. Every intended clearing of wood-land, and espe-
cially of those under a second growth of pines, ought to be marled
before cutting down ; and it will be still better if it can be done
several years before. If the application is delayed until the new
land is brought under cultivation, though much putrescent matter
will be saved, still more must be wasted. By using marl some
years before obtaining a crop from it, as many more successive
growths of leaves will be converted to useful manure, and fixed in
the soil ; and the increased fertility will more than compensate for
the delay. By such ai> operation, the farmer makes a loan to the
soil, at a distant time for payment, but on ample security, and at a
high rate of compound interest.

Some experienced (though certainly not land-improving) culti-
vators have believed that the most profitable way to manage pine
old fields, when cleared of their second growth, was to cultivate
them every year, until worn out — because, as they said, such land
would not last much longer, no matter how mildly treated. This
opinion, which would seem at first so absurd, and in opposition to
all the received rules for good husbandry, is considerably supported
by the properties which are here ascribed to such soils. When
these lands are first cut down, an immense quantity of vegetable
matter is accumulated on the surface, which, notwithstanding its
accompanying acid quality, is capable of making two or three crops
nearly as good as the land was ever before able to bring. But as
the soil has no power to retain this vegetable matter, it will begin
rapidly to decompose and waste, as soon as exposed to the sun ;
and will be lost, except so much as is caught, while escaping, by
the roots of growing crops. The previous application of marl,

168 EFFECTS ON "FREE LIGHT LAND."

however, would make it profitable in tlieso, as well as other cases,
to adopt a mild and meliorating course of tillage.

Less improvement will be obtained by marling worn soils of the
kind called " free light land/^ than other acid soils which originally
produced much more sparingly. The early productiveness of this
kind of soil, and its rapid exhaustion by cultivation, at first view
seem to contradict the opinion that durability and the case of im-
proving by putrescent manures are proportioned to the natural
fertility of the soil. But a full consideration of the circumstances
will show that no such contradiction exists.

In defining the term natural fertility ^ it was stated that it should
not be measured by the earliest products of new land, which might
be either much reduced, or increased, by temporary causes. The
early fertility of free light land is so rapidly destroyed, as to take
away all ground for considering it as fixed in, and belonging to the
soil. It is like the efi"ect of clung on the same land afterwards,
which throws out all its benefit in the course of one or at most two
years, and leaves the land as poor as before. But still it needs
explanation why so much productiveness can at first be exerted by
any acid soil, as in those described in the 14th experiment. The
causes may be found in the following statement. These soils, and
also their sub-soils, are principally composed of coarse sand, which
makes them of more open texture than best suits pine, and (when
rich enough) more favoui*able to other trees, the leaves of which
have no natural acid, and therefore decompose more readily. As
fast as the fallen leaves rot, they are of course exposed to waste ;
but the rains convey much of their finer p^ts down into the open
soil, where the less degree of heat retards their final decomposition.
Still this enriching matter is liable to be further decomposed, and
to final waste \ but though continually wasting, it is also continu-
ally added to by the rotting leaves above. The shelter of the
upper coat of unrotted leaves, and the shade of the trees, cause
the first as well as the last stages of decomposition to proceed
slowly, and to favour the mechanical process of the products being
mixed with the soil. But there is no chemical union of the vege-
table matter with the soil. When the land is cleared, and opened
by the plough, the decomposition of all the accumulated vegetable
matter is hastened by the increased action of sun and air, and in
a short time everything is converted to food for plants. This
abundant supply sufiices to produce two or three fine crops. But
now, the most fruitful source of vegetable matter has been cut off;
and the soil is kept so heated (by its open texture) as to be unable
to hold enriching matters, even if they were furnished. The land
soon becomes poor, and must remain so, as long as these causes
operate, even though cultivated under the mildest rotation. When
the transient fertility of such a soil is gone, its acid qualities

OPERATION OF DEEPENING SOIL.

(wliicli were before concealed in some measure by so much enrich-
ing matter) become evident. Sorrel and broom-grass cover the
land, and if allowed to stand, pines will then take complete pos-
session, because the poverty of the soil leaves them no rival to
contend with.

Marling deepens cultivated sandy soils, even lower than the
plough may have penetrated. This was an unexpected result, and
when first observed seemed scarcely credible. But this effect also
is a consequence of the power of calcareous earth to fix manures.
As stated in the foregoing paragraph, the soluble and finely divided
particles of rotted vegetable matters are carried by the rains below
the soil ; but as there is no calcareous earth there to fix them, they
must again rise in a gaseous form, after their last decomposition,
unless previously taken up by growing plants ; [or descending still
lower in the sub-soil, dissolved in rain-water, may go off into the
sources of springs, and so be lost to the land.] But after the soil
is marled, calcareous as well as putrescent matter is carried down
by the rains as far as the soil is open enough for it to pass. This
will always be as deep as the ploughing has been, and somewhafc
deeper in loose earth; and the chemical union formed between
these different substances serves to fix both, and t!ms increases the
depth of the soil. This effect is very different from the deepening
of a soil by letting the plough run into the barren sub-soil. If,
by this mechanical process, a soil of only three inches is increased
to six, as much as it gains in depth, it loses in richness. But when
a marled soil is deepened gradually, its dark colour and apparent
richness are increased, as well as its depth. Formerly, single-horse
ploughs were used to break all my acid soils, and even these would
often turn up sub-soil. The average depth of soil on old land did
not exceed three inches, nor two on the newly cleared. Even be-
fore marling was commenced, my ploughing had generally sunk
into the sub-soil — and since 1825, most of this originally thin soil
has required three mules, or two good horses to a plough, to break
the necessary depth. The soil is now from six to eight inches
deep generally, from the joint operation of marling and deepening
the ploughing a little in the beginning of every course of crops ;
[and to that depth, or very nearly, the land is now ploughed when-
ever preparing for corn, or for wheat on clover. The summer
ploughing of clover land requires four mules to a plough.

Since marling was begun, the deepening of the soil has much '
more generally preceded than followed the deepening of the plough-
ing. How destructive to the power of soil this present depth of
ploughing would have been, without marling, may be inferred from
the continued decrease of the crop, through four successive courses
of a very mild rotation, on the spot kept without marl in experi-
ment 10. Yet the depth of ploughing there did not exceed six
15

170 HASTENING MATURITY Or CROPS.

inclies, and depths of nine and even twelve inches were tried, with-
out injury, on parts of the adjacent marled land. — 1835.]

[This remarkable and valuable effect of marling, in deepening
the soil, is increased in action bj the sub-soil being sandy, which
is commonly deemed the worst kind of sub-soil. Land having a
clay sub-soil, vrhich is known in common parlance as land with '■^ a
good foundation,'^ is almost universally prized ) and that impervi-
ous sub-soil is supposed necessary to prevent the manure and the
rains from sinking, and being lost. And such, indeed, may be
among the disadvantages, before marling, of poor land having a
sandy sub-soil. But not so after marling. While the open texture
of such a sub-soil permits so much of the water as is superfluous
and injurious to sink and disappear, and the combined manures to
sink enough to deepen the soil (by converting barren sub-soil to
productive soil), the attractive force of the calcareous earth, for both
putrescent matter and moisture, will much more effectually prevent
either from being lost to the soil, than would the mechanical ob-
struction of a clay sub-soil. Great as are the objections enter-
tained by most farmers to sandy sub-soils, or to what they call
" land without any foundation,'^ I would decidedly prefer such to
lands having aft^ impervious clay sub-soil — supposing both to be
equally barren. The subjects of all my experiments stated as
made on acid sandy loams, had also sub-soils of yellow and barren
sand ] and on such lands have been made my greatest and most
profitable improvements by marling. However, a sub-soil (and
also a soil) more of medium texture, would no doubt have been a&
much better than the very sandy, as the latter was better than the
very stiff and impervious clay sub-soils. — 1842.]

[Besides the general benefit which marling causes equally to all
crops, by making the soils they grow on richer and more productive,
there are other particular benefits which affect some plants more
than others. For example, marling serves to make soils warmer,
and thereby hastens the ripening of every crop, more than would
take place on the like soils, if made equally productive by other
than calcareous manures.* This quality of marled land is highly
important to cotton, as our summers are not long enough to mature
the later pods.

Wheat also derives especial benefit from the warmth thus added
to the soil. It is enabled better to withstand the severe cold of
winter ; and even the short time by which its ripening is forwarded
by marling, serves very much to lessen the danger of that crop

* Confirmation. — ^^ Liming hastens the maturity of the crop. — It is true of
all our cultivated crops, but especially those of com [wheat] that their
growth is attained more speedily when the land is limed, and that they are
ready for the harvest from 10 to 14 days earlier." Johnston's Lectures^
p. 392.

PECULIAR BENEFITS TO WHEAT, ETC. 171

from rust, tlie most frequent and destructive of all its diseases.
This, much more than any other grain crop, seems to be especially
favoured by calcareous earth in the soil. The product is not only
always much increased, but other accessary effects are produced,
for want of which on the lands most highly manured, but still defi-
cient in lime, the wheat crop is made feeble, and in danger of great
loss or destruction from different disasters. Thus, if a heavy
growth of wheat is produced by putrescent manures only, the straw
is weak, and the crop is almost sure to be laid by its own weight
before ripening, even without stormy weather, and is very much
reduced in value. On limed or calcareous land, the crop is far
safer ; and is seldom laid, even when very heavy, unless by violent
storms, which is owing to the greater strength of the straw.* The
opening of the texture of close clay soils by the operation of cal-
careous manures, by permitting the better percolation of surplus
water, serves in some measure as drainage, and especially enables
wheat better to withstand the always redundant wet of winter on
such soils, which is much more the cause of ^' winter-killed'^ wheat,
than the severity of cold, or alterations of temperature. Wheat
also profits by the absorbent power of marled land (by which sands
acquire, to some extent, the best qualities of clays), though less
so than clover and other grasses that flourish best in a moist
climate.

Indian corn does not need more time for maturing than our sum-
mers afford (except on the poorest land), and can sustain much
drought without injury, and therefore is less aided by these quali-
ties of marled land. Most (if not all) the different plants of the
leguminous or pod-bearing tribe, including all the varieties of clo-
ver, peas, and beans, derived such peculiar benefit from marling,
that it indicated some peculiar operation on these plants. What
this is, has recently been made clear by the researches of chemists.
The analyses of the ashes of leguminous plants show that they
contain very large proportions of lime, and far exceeding those of
any other cultivated plants. Of course, they need a larger and
ready supply of lime in the soil ; and they profit in proportion to
their wants, by such supply being furnished. — 1845.]

On acid soils, without heavy manuring, it is scarcely possible to
raise red clover ; and even with every aid from putrescent manure,
the crop will be both uncertain and unprofitable. The recommenda-
tion of this grass, as part of a general system of cultivation and
improvement, by the author of ^ Arator,' is sufficient to prove that
his improvements were made on soils far better than such as are
common. Almost every zealous cultivator and improver (in prospect)
of acid soil has been induced to attempt clover culture, either by

-^ This effect is also affirmed by Johnston, p. 392.

172 PECULIAR BENEFXT TO CLOVER.

the recommendations of writers on this grass, or by the suecesg
witnessed on better constituted soils elsewhere. The utmost that
has been gained, by any of these numerous efforts, has been some-
times to obtain one, or at most two mowings, of middling clover,
on some very rich lot, which had been prepared in the most perfect
manner by the previous cultivation of tobacco. Even in such
situations, this degree of success could only be obtained by the
concurrence of the most favourable seasons. Severe cold, and
sudden alternations of temperature in winter and spring, and the
spells of hot and dry weather which we usually have in summer,
were alike fatal to the growth of clover, on so unfriendly a soil.
The few examples of partial success never served to pay for the
more frequent failures and losses 3 and a few years' trial would
convince the most ardent, or the most obstinate advocate for tjae
clover husbandry, that its introduction on the ordinary poor soils
of lower Virginia was absolutely impossible ; and scarcely practi-
cable, even partially, on such lands when very highly manured.
Still the general failure was, by common consent, attributed to any-
thing but the true cause. There was always some reason offered
for each particular failure, sufficient to cause it, and but for which
(it was supposed) a crop might have been raised. Either the
young plants were killed by freezing soon after first springing from
the seed — or a drought occurred when the crop was most exposed
to the sun, by reaping the sheltering crop of wheat — or native and
hardy weeds, aided by very favourable weather, overran the crop ;
and all such disasters were supposed to be increased in force, and
rendered generally fatal, by our sandy soil, and hot and dsy sum-
mers. But after the true evil, the acid nature of the soil, is re-
moved by marling, clover ceases to be a feeble exotic. If with-
standing the early dangers of frost on the newly sprouted plants,
and of drought soon after, clover is then naturalized on our soil,
and is able to contend with rival plants, and to undergo every
severity and change of season, as safely as our crops of corn and
wheat — and offers to our acceptance the fruition of those hopes of
profit and improvement from this grass, with which previously we
had only been deluded.

After much waste of seed and labour, and years of disappointed
efforts, I had abandoned clover as utterly hopeless. But after
marling the fields on which the raising of clover had been vainly
attempted, there arose from its scattered and feeble remains, a
growth which served to prove that its cultivation would then be
safe and profitable. It has since been gradually extended over all
the fields. It will stand well, and maintain a healthy growth on
the poorest marled land ; but the crop is too scanty for mowing, or
perhaps for profit of any kind, on most poor sandy soils, unless
aided by gypsum. Newly cleared lands yield better clover than

THE BAD WEEDS PRODUCED BY CALXING. 173

the old, though the latter may produce as heavy grain crops. The
remarkable crops of clover raised on some very poor clay soils, after
marling, have been already described. This grass, even without
gypsum, and still more if aided by that manure, will add greatly
to the improving power of marl ; but it may do as much harm as
service, if we greedily take from the soil all of the supply of
putrescent matter which it aifords.'*'

Some other plants, less welcome than clover, are equally favoured
by marling. Unless both the tillage and the rotation of crops be
good, greensward (^poa pratensis), blue grass (^poa comjjressa) ,
wire-grass {cynodon dactylon), and the vetch, or partridge pea
(vicia sativa)y will soon increase so as to be not less impediments
to tillage, or to the grain crops, than manifest evidences of an
entire change in the character and power of the soil.

[The power of calcareous manures is still more strongly shown
in the eradication of certain plants, as has been before incidentally

[* There is great difl&culty, and frequent failure of securing a " stand"
of tlie young clover plants, even when the subsequent growth of those
which escape early destruction is ever so vigorous. This is not owing to
any defect of soil (after calxing), but to our climate. It is necessary to
sow clover seed before the close of winter, to avoid, by its early growth,
the greater evils of the following summer's drought, which most affects the
youngest plants. The time of sowing is usually not later than February.
It almost always happens that a succeeding warm spell causes most of the
seeds to sprout, and then a severe frost kills them, while in their most
tender state. Sometimes, the whole young growth is thus killed by late
frosts. The danger from drought, and the hot sun, after reaping the
shading cover of wheat, is scarcely less than from frosts at the earlier
period. One or both of these disasters have occurred for four of the first
five seasons for my sowing clover on Marlbourne ; so that but one good
"stand" of plants, and of course but one sufficiently thick crop was ob-
tained. The loss was the greater, because no clover had previously been
on the land, and, of course, there was no volunteer growth, which other-
wise and usually furnishes as many plants as the new seed. Indeed, after
a field has once been well covered with clover, and the ripe seeds ploughed
under, there is not half the danger at any time afterwards of failing to
secure a stand of plants.

But a greater evil has been found than this, since the publication (in
18-42) of the passages above reporting so favourably of the growth and
hardiness of clover. On the Cogglns farm, and elsewhere, on ih.Q formerly
acid soils marled more than twenty years ago, the clover crops have recently
been much more apt to fail, as above, and are much inferior in product,
even when not failing to stand, than previously ; and this where the land
certainly has not lost anything of its richness, and where other crops than
clover show no diminution. It is not certain whether this change is owing
to the land being "clover-sick," (a common result in England, but not
known here, before), or that the acid of the soil (or sub-soil) is increasing
and overbalancing the quantity and effects of the calcareous earth. Some
facts sustain this latter supposition. Ilemarlings, at lighter than the earlier
rate, have been found, in some cases, to restore the before reduced power
of the land to produce clover. — 1849.]
15*

174 ACID PLANTS ERADICATED.

mentioned. Sorrel (rumex acetocella) is the most plentiful and
injurious weed on the cultivated acid soils of lower Virginia ; an
unmixed growth of poverty grass (aristida gracilis) is spread over
all such lands, a year after being left at rest ; at a somewhat later
time broom-grass (andropogon) of different kinds covers them
completely; and if suffered to remain unbroken a few years longer,
a thick growth of young pines will succeed. But as soon as such
land is sufficiently and properly marled, there remains no longer
the peculiar disposition or even power of the soil to produce these
plants. Sorrel is totally removed, and poverty grass no more is to
be found, where both in their turn before had entire possession.
The appearance of a single tuft of either of these plants is enough
to prove that the acid quality of the soil on that spot still remains,
and that either more marl, or more complete intermixture, is still
wanting. Thus, the presence of either of these plants is the most
unerring as well as most convenient and ready indication of a soil
wanting calcareous manure. The most laborious analyses, by the
most able chemists, directed to ascertain the different characters
of soils in this respect, are not to be compared for accuracy to the
tests furnished by either the appearance or total absence of sorrel
or poverty grass. In regard to broom-grass and pines, the change
is not so sudden, or complete ; but still the soil will have been
made manifestly unfriendly to both. Some striking apparent ex-
ceptions to these rules have caused some persons to doubt of their
correctness, when full examination of the circumstances would
have confirmed my positions. I have known a mere top-dressing
of marl, left for some years on a worn-out old field, to eradicate
the before general growth of broom-grass, and substitute a cover
of annual weeds. Yet on other tillage land, after marling and one
crop of wheat on fallow, I have seen the growth of broom-grass
return, and seemingly with greater than its former vigour. But
this return and vigour were but temporary, and the land is now
comparatively free from this injurious weed. When soil, already
filled with its seeds, is very imperfectly mixed with marl by plough-
ing, there is nothing to prevent the broom-grass springiug from all
the spots not touched by the marl, whether these spots be above
or below or between unmixed masses of marl. And the growth
being thin and scattered, and not covering the surface completely
as formerly, will cause the separate tufts of broom-grass to be
much more luxuriant, and greater impediments to tillage, than
previously. But the next course of tillage will^erve to mix the
marl and soil completely, and remove all this appearance of marl
being favourable, instead of destructive to broom-grass. Sorrel
may often be seen growing out of the heaps of pure marl, dropped
from the carts on acid land, and the heaps left thus, unspread,
through a summer. But this apparent and very striking exception

DIFFICULTIES WITHOUT CAUSE. 175

may bo fully explained. The heaps of marl, thus left, had not as
yet by any intermixture affected the original composition of the
soil below ; and the seeds or roots of sorrel therein were therefore
free to spring and grow ; and the great hardiness and remarkable
vital power of that plant enabled it to rise through the (to it) dead
matter and great obstruction of several inches thickness of pure
marl above. On examining the roots of sorrel thus growing out
of marl, it will be seen clearly, and invariably, that they drew all
their support from the still acid soil below, and merely passed
through trhe marl, without drawing anything therefrom.*]

CHAPTER XX.

DIRECTIONS FOR THE USE OP MARL IN CONNEXION WITH OTHER
FARMING OPERATIONS.

Proposition 5 — continued.

From the foregoing reasoning and statements, the general course
most proper to pursue in using calcareous manures, and for cultiva-
tion in connexion with them, may be well enough deduced. But
as I have found that, notwithstanding all such aids, many persons
Btill require and apply for more special directions to guide their
operations, the following suggestions and remarks will be offered,
at the risk of their being deemed superfluous. These directions,
like all the foregoing reasoniug, may apply generally, if not en-
tirely, to the use of all kinds of calcareous manures, and to soils
of every region. But to avoid too wide a range, I shall consider
them as applying more especially to the lands of the tide-water
region ; and as addressed to farmers who have just begun the im-
provement of such lands, by means of the fossil shells or marl of
the same region.

JMauy persons, at first, attach much importance to some of the
conditions of marling which I deem scarcely worth consideration.
Numerous inquiries have been addressed to me for the purpose of

* In England the effect of lime in preyenting the growth of sour plants
is stated by Johnston, thou|h most of the plants are different from ours
of that character. ElscAvhcre he speaks doubtfully, and upon report only,
of calcareous manure eradicating sorrel. He says, liming •• kills heath,
moss, and sour and benty {agrostis) grasses, and brings up a sweet herbage,
mixed with red and white clovers." "All fodder, whether natural or arti-
ficial, is said to be sounder and more nourishing when grown upon land to
>yhich lime has been applied abundantly. On benty grass the richest
animal manure often produces little improvement, until a dressing of lime
has been laid on." p. 391.

176 PROPER PROCEDURE OF BEGINNERS.

learning, in the case of eacli particular applicant for directions, at
what time and in what manner to apply marl, and which of different
kinds of marl to prefer for different soils. There would be but
small danger of misleading any one, if to all such inquiries this
one general answer were given : '^ Put on the most accessible marl,
over as much land as possible, and speedily, without regard to any
attendant circumstances whatever." If the soil requires marling
(and there are scarcely any exceptions in lower Virginia), and the
available bed is truly and sufficiently calcareous, there can be no
important error made in applying it, except by too heavy -dressings,
or by very unequal spreading. If merely avoiding these two
errors, I should deem that procedure the best by which the new
beginner can put on his fields the greatest quantity of calcareous
earth in the shortest time.

But though comparatively of little importance, still there are
advantages and disadvantages to be found in the circumstances to
which so much undue importance has been attached. These I will
proceed to remark upon.

To marl extensively or economically, it is essential (as has been
before stated) to devote to this business a certain labouring force,
either for the whole year, or for such certain parts of the year as
may be deemed more proper ; and for the time this force shall be
so directed, the proprietor must not allow the labour to be diverted
to any other object. If he draws upon the marling force whenever
he or his overseer thinks the labour is needed to forward other farm
operations, it will soon be found that the marling will be generally
suspended ) and yet, in all probability, the other labours be not the
better performed because of this always ready resource for extra
aid.

Then supposing that the marling is going on throughout the
year, or through different designated portions of the year, it is
obvious that the marl cannot be always applied to any one condition
of the land. In the beginning, the new marler should aim to cover
as much land as possible for his next corn or other tillage crop.
After that crop shall have been planted, the marling can proceed
no farther on that field; and the operation will be then commenced
on the field for corn tillage the following year. It is much better
that marling should be followed first by some tilled crop ; so that
the different ploughings and harrowings shall well mix the marl
and soil throughout, to the depth of the ploughing. This mixing
is best and most certainly effected, when the marl has been spread
over the ploughed surface. The subsequent shallow tillage, by
small ploughs, cultivators, harrows, and hand-hoes, at every move-
ment continually stirs and mixes the marl with the soil.

But if the subsequent tillage processes should be such as to
effect the object of mixing the marl and soil intimately, I would

INTERMIXTURE OF MANURE AND SOIL. 177

prefer spreading the marl before plougliing, on the vegetable cover
of the land. When thus placed in contact with the putrescent
matter, it has seemed to me that the marl acted more speedily and
better. But, if marl be thus applied on the grass and ploughed
under, the first ploughing should not be deeper than will be at
least one thorough ploughing for the subsequent tillage of the first
crop. Otherwise, the marl will not be mixed with the soil above,
and will remain unchanged and inert in the masses, whether soft
and loose, or lumpy, as turned under by the plough. In such
cases, the marl can have but little effect, until brought up again by
as deep a ploughing, perhaps some years after.

Each of these modes of applying marl then has different ad-
vantages; and may have also disadvantages, if they be not
guarded against. But in either mode, by proper care, the important
condition of suiBScient mixture of the marl and soil may be secured.
When marl must be ploughed under (for a corn crop), it is import-
ant that the first ploughing should be as shallow as consistent with
good culture, and that the tillage, in part, shall be fully as deep.
If it be preferred to spread marl on the ploughed surface, that
may be done, for the greater part of the land, even after dropping
the marl, throughout the previous summer, on the grassy surface.
For this purpose, the marl heaps must be dropped accurately along
the middles of beds, if the land was then in beds designed to
be reversed; or along parallel lines, marked by the plough, if
not in beds. The spreading must be postponed until after the in-
tervals of land between the rows of marl shall have been ploughed -
for the next crop, leaving merely the narrow strips on which the
heaps lie. In this manner, from two-thirds to three-fourths of the
whole surface is ploughed before the spreading of the marl. This
is next done, over the whole surface, after which the before omitted
strips are ploughed.

After the first year, generally, the farmer may be able to marl
fast enough to keep ahead of his cultivation ; and even should he
(to effect that end) reduce the extent of his previous tillage one-
half, it will be best for him not to put an acre under crop which
has not been first marled. Fifty acres can, in most cases, be both
marled and tilled at least as cheaply as one hundred can be tilled
without marling ; and the fifty with marl will usually (if on soil
before acid), produce as much in the first course of crops as the
hundred without, and much more afterwards.

The most important auxiliary to marl, is to supply vegetable
matter (or any putrescent matter) to the land. The cheapest and
most efficient means, and especially for poor lands having no foreign
sources of supply, will be found in tlie non-grazing system, by
which the land, when not under cultivation, manures itself, by the
growth, and death, and decay of its own wecd^ and grass. Poor

178 VEGETABLE MATTER ESSENTIAL.

and scanty as may be such products and such manuring of poor
lands, they very much exceed any substituted supplies ; and more-
over cost nothing.*

That rotation of crops which gives most vegetable matter to the
soil, is best to aid the effects of marl recently applied. The four-
shift rotation is convenient in this respect, because two or three
years of rest may be given in each course of the rotation at first,
upon the poorest land ; and the number of exhausting crops may
be increased, first to two, then to three in the rotation, as the soil
advances to higher states of productiveness. But it is only while
land is poor that I would advise the four-shift rotation, with as
much as two years rest in the course j or the entire exclusion of
grazing under any rotation. Both tend to make the fields foul with
both weeds and insects; and when the land has been under such
treatment for some 8 or 10 years, and has been made richer as well
as fouler thereby, it will be expedient to graze moderately and
judiciously, and to adopt a difi'erent and better rotation.

After marling, clover should be sown, and gypsum on the clover.
On poor, though marled land, of course only a poor growth of
clover can be expected ; but wherever other manures are given,
and especially if gypsum is found to act well, the crop of clover
becomes a most important aid to the improvement by marling.

* If there is one of the requisitions or accompaniments of marling
more insisted on than all others — and both by my theoretical views and
practical instructions — in all my -writing on this subject — it is the necessity
for providing organic (or putrescent) manure for all land in full proportion
to the calcareous earth supplied. Without this being done, not only will
the early eifects of the calxing be small, but, in the end, the land will be
more completely exhausted of its actual organic ingredient, and conse-
quently and ultimately of its fertility, than if it had not been calxed. It
is not necessary, however, that all the required organic manure shall be
furnished from the stable and stock-pens — or shall even be what is ordina-
rily termed manure. As much of this as may be available should be ob-
tained from these sources. But a much larger supply, and far more
cheaply, will be furnished by the fields themselves, in their vegetable
cover, whether of clover or weeds, suffered to grow and to die and rot on
or under the soil. This is the natural and the greatest source of supply
of organic manure to the calxing farmer — and which he can increase to
any desired extent, by merely giving more time for the land to rest from
tillage, and to produce more of alimentary or mijnuring growths.

But as often and as strongly as I have urged the indispensable necessity
for this course, scarcely any of my disciples have obeyed the injunction
fully and properly. Nine out of ten of all the farmers who have used
marl, and to great profit, still have drawn too heavily from their land, and
are lessening, instead of continuing to increase, the fund of productive
power in the soil, which calxing had made active. But with this important
truth they cannot be impressed. They cannot be persuaded that they are
operating to exhaust their fields, while they still continue to derive from
them crops three-fold greater than fonnerly could be grown.

ORGANIC MANURES. 179

Without clover, and without returning the greater part of the early
product to the soil, the greatest value of marling will not be seen.
A small proportion of the clover may be used for mowing and
grazing ; and in a few years even this small share will far exceed
all the grass that the fields furnished before marling and the limit-
ation of grazing. This limitation, which is at first objected to as
lessening the food of grazing stock, and their products, within a
few years becomes the source of a far more abundant supply of
both.

During the first few years of marling, but little attention can
(or indeed ought to) be given to making putrescent manures, be-
cause the soil much more needs calcareous manure j and three or
four acres may generally be supplied with the latter, as cheaply as
one with the former. But putrescent manures cannot anywhere be
used to so much advantage as upon land after being made calcare-
ous ; and no farmer can make and apply vegetable matter as ma-
nure to greater profit than he who has marled his poor fields, and
can then withdraw his labour from applying the more to the less
valuable manure. After the farm has been marled over at the
light rate recommended at first (say 200 to 300 bushels), every
effort should be made to accumulate and apply vegetable manures ;
and with their gradual extension over the fields, a second applica-
tion of marl may be made, making the whole quantity, in both the
first and second marling, 500 or 600 bushels to the acre, or even
more ; which quantity might have been hurtful if given at first,
but which will now be not only harmless, but necessary to fix and
retain so much putrescent and nutritive matter in the soil.

The above injunction, that " every effort should be made to ac-
cumulate and apply vegetable manures,'^ should not be limited, as
most new improvers would be apt to do, to the mere economical use
of the vegetable materials for manure furnished by the crops, and
those only as prepared by being first used as litter for animals.
Not only these, but every other vegetable and putrescent material
that is accessible should be saved and applied, and even without
any intermediate process of preparation, and at any time of the
year, and state of the fields, provided no growing or commencing
crop be thereby molested. Surplus straw, not needed for food or
litter, is most valuable and cheaply applied as top-dressing to clover
or other grass ; though it is an inconvenient and troublesome ma-
nure if soon after to be ploughed under. Leaves from the woods
of the farm may be used most profitably in the same manner, to
the full extent of the resources offered. And though the manuring
operations on the Coggins Point farm have not yet been extended
beyond the last-named putrescent material (and of that, not to
much extent), it is believed that other and abundant sources yet
remain untried and unproductive on that and most other farms, and

180 RESOURCES TOR ORGANIC MANURES.

to use wbicb would be but a waste of labour or money, if in ad-
vance of marling. Among the most abundant of such materials,
may be mentioned marsh grasses and marsh or pond mud, espe-
cially if used in compost ; and also the purchase of rich alimentary
manures from towns, to be carried by land or by water carriage to
much greater distances than has yet been done, or can be afforded
to be done, on other lands. Even saw-dust and spent tanner's
bark, which, because of their insolubility, are generally deemed of
no value as manures, would form important and valuable materials
for fertilization, in situations where they can be obtained cheaply
and in great quantity. Mixing these or other insoluble vegetable
substances with rich putrescent matters, and still more if with
some alkaline matter also, would render them soluble, and convert
them to food for plants. These inert substances would be most
profitably used as litter for stables and cattle pens in summer, where
the ordinary more decomposable materials are too quickly rotted,
and subject to great loss thereby.

But putting aside the consideration of all such unusual or un-
tried resources and operations for additional fertilization, and limit-
ing the present view merely to the ordinary materials furnished by
the fields of every farm, the progress and profit of improvement
by such means only, after marling, will be greater than will be at
first believed by most cultivators of acid soils, not yet marled or
limed. If, on such soils, the general course above advised be pur-
sued (and using merely the resources of the farm after marling),
the products of crops on all the marled land usually will be doubled
in the first course of the rotation — often in the first crop immedi-
ately following the marling; and the original product may be
expected to be tripled by the third return of the rotation. And
this may be from merely applying marl in sufficient (and not ex-
cessive) quantities, and giving the land two years' rest in four
without grazing. But on the parts having the aid of farm-yard
and other putrescent manures, and of clover, still greater returns
may be obtained.

CHAPTER XXI.

ACTUAL IMPROVEMENTS AND RESULTS OP MARLING. PECULIAR
VALUE OP SANDY SOILS.

Proposition 5 — continued.

When sucli promises of improvement and of profit from marling
are stated as in the preceding chapter, there will naturally occur to
the mind of every inexperienced reader the questions, "Has the
writer himself met with so much success — and what have been the
actual results of his labours in the mode of improvement which he
so strongly recommends V From these questions the writer has
no excuse for shrinking ; though to answer them there must neces-
sarily be obtruded much egotism, and references made to many
trivial details, which are certainly not worth being offered to public
notice, except as explanatory and in support of the more general
and important facts asserted in this essay.

In answer, then, to these supposed questions, I have to admit
that, in my earlier marling labours, the progress of fertilization
was not so rapid, in general, and the average profits therefrom not
so great, as might be expected from the general views and antici-
pations stated in the last preceding chapter ; though, more recently,
the benefits have been much greater, and full as profitable as were
anticipated, or could be counted upon, from the foregoing views
applied to the existing circumstances of the lands under the opera-
tions. Among the sufiicient causes of the stated slower improve-
ment, and lower profits of my earlier labours, were the following :

1st. The greater part of my land, on the Coggins Point farm in
Prince George county, was not of either such surface or soil as is
adapted for the greatest improvement by calxing : some having
been naturally calcareous, and therefore not needing marl ; and a
large part of the farm, where hilly or even of undulating surface,
having lost more or less of its soil — and on very many slopes, all
the soil — by the washing rains acting on bad tillage.

2d. Having at first everything to learn in regard to the practice,
and to prove by actual trial, without any light from either expe-
rience, or the prior or cotemporary operations of other farmers,
much of my labour was lost uselessly in wrong procedure , or was
worse spent in excessive applications of marl, which subsequently
proved to be injurious.

3d. The fitness given to the before acid soil, by marling, to pro-
duce clover, was not found out, until several years after that best
auxiliary to the first improvement ought to have been in full use.
16 (181)

182 CAUSE OF DEFECTIVE RESULTS.

4th. Because of the want of enough labour to use properly both
calcareous and putrescent manures, the collecting and applying of
the latter were greatly neglected as long as there was full employ-
ment in and need for marling.

5th. The adoption of cotton culture, for five years, occupied for
that crop and for that time the best land of the farm, and some-
times the whole of the very good land, and took all the prepared
putrescent manure, to the great diminution of other crops ; while
this culture caused (by its clean and continual tillage) more wast-
ing of soil, and more detriment to general fertilization, than grain
and clover husbandry.

6th. The general bad practical management, and want of economy
in details, which, I have to confess, have attended all my business,
and throughout my life, of course injuriously affected this import-
ant branch of my farming ; though in a less degree, because it was,
as much as possible, kept under my personal and close attention.

7th. In 1827, my residence was removed from my farm, and my
personal attention much decreased ; and some years later was en-
-tirely withdrawn.

To what extent all these drawbacks to full success operated, ag
well as the actual degree of success achieved, may be inferred from
the tabular statement of the crops made, both before and since
marling, and from 1813 to 1851. The much greater increase of
production obtained in later years on the Coggins Point farm was
mainly owing to the adoption of a better rotation of crops, includ-
ing clover-fallow for wheat, and to the residence, and personal and
judicious direction of my eldest son, who since the beginning of
1839 has been the occupant of the farm (and more lately the sole
proprietor), and, throughout this time, the sole director of its cul-
tivation and general management. Until this change of direction
occurred, the actual measure of productive power in the land,
which had been created by the marling, was not known. A large
share of this power, before dormant and concealed, was now brought
for the first time into action, and made apparent. The like condi-
tions of residence, attentive supervision, and a better system of
rotation, in my own case, also greatly hastened and increased the
success of my later marling labours ("resumed after a long diversion
of my efforts to different objects), m a new locality, and under
very difficult and also very different circumstances from those of
my earlier farming. These recent labours, and the results, will
again be brought forward.

The following general statement of the then condition of the
farm was published in 1842. The still later and much greater
productiveness will appear in the annexed table of crops, which
will be now extended so as to include the latest obtained.

The many and extensive old galled parts of sloping land,

ACTUAL REStJLTS ON COGGINS FAEM. 183

wlierever dressed with marl, and even without the further help of
barn-yard manure, are now nearly all skinned over by a newly
formed soil ; and though such soil is still both poor and thin, and
may yet long remain so, the ichole of its present productive power
is due to marling ] as such galled land was before naked, entirely
barren, and irreclaimable by other manures. Where much or rich
putrescent matter has been also applied to galls, with or after marl,
both rich and durable soil has been formed, though at great cost.

The more level parts of the old and greatly exhausted fields, and
the newly cleared wood-land (both kinds being naturally poor, thin,
and acid soils), are the only lands which have enjoyed anything
like the full beneficial effects of marling. These have been in-
creased in product from 5 and 10 bushels of corn per acre (which
may be considered the usual minimum and maximum rates), to at
least 20, and in some cases to 30 bushels, even without the aid of
barn-yard manure. Where putrescent manures have been also
applied, they have raised the products much higher ; and these
manures are now as durable and as profitable as formerly they were
fleeting and profitless in effect.

The before poor and light soil which formed the greater part of
the old arable lands, and which was not above three inches in depth
(and scarcely two inches when in its natural forest state), is now
seven inches or more, and requires three-horse ploughs to break it
to proper depth, where the one-horse ploughs formerly would fre-
quently reach and bring up the barren sub-soil.

The fertilizing operation of marl has increased with time, even
where the efi"ects were also the most speedy, and most profitable on
the first crop after the application.

The soil, which before was totally unable to support red clover,
is now (except on the most sandy spots) well adapted to the growth,
and capable, according to the grade of fertility, of receiving the
great benefit which is ofi"ered by that most valuable of improving
crops.

And generally — notwithstanding all the many and great errors
committed in my marling (for want of experience), and of still worse
general farm management — and though a considerable proportion
of the old land was either but little or not at all fit to be improved
by marling — and though the land added since by new clearings was
all very poor, and worthless for its natural producing power — still,
the general annual grain products of the farm have been increased
'from three to four-fold, and the net profit of cultivation and the
intrinsic value of the land have been increased in a still greater
proportion . — [1 842 . ]

1«4^

INCREASE OP CROPS FROM MARLING.

Statement of marling and crops j on Coggins Point (jiow Beech'
wood) Farm.^^

1

s

WHEAT. 1

CORN. 1

-^

0 — <

8)0

m

00

M "S

^ a^

CS u

CO

'0

a u

u

4)

OJ S

f-t «

0

r^

u 0

is

U

II

0 '^ 2

<1> ei

u

CO

<a (A

1813

<

0

U 0

5^

0

<1

!3

^S

145

810

5.58

125

2250

18.

1814

0

110

550

5.

163

1340

8.18

1815

0

78

520

6.67

186

1955

14.38

181G

0

104

896

8.61

144

2300

16.90

1817

0

79

595

7.52

188

2050

10.90

1818

fl5

63

450

7.14

a 160

*2670

16.68

1819
1820

62
25

132

1015
1020

7.69
8.57

a 137
a 164

*2000

14.59
17.

119

*2780

B a

1821

80

160

1049

6.56

a 77

§1775

23.

^ -2

0 a

03 0

1822

93

154

1627

10.56

all4

*2250

19.73

Si

1823

100

139

1475

10.61

158

*3000

19.

<^

1824

1825

80
50

194
195

1850
1452

9.54

7.45

156
70

*3405
1254

21.80
17.91

48

1826

24

170

1390

8.17

188

*2275

16.48

70

1827

im

151

1366

9.04

104

*1665

16.

76

37il

1828

.0

153

936

6.12

112

1750

15.62

90*

55

1829

.0

134

908

6.78

133

2300

17.37

96

1830

50

—

—

■^

501-

33

1831
1832

1835

0
0

2160

« —

0

—

126

2830

22.46

4000

1836

10

184

e394

2.17

4415

QO

t> 00

1837

0

147

2056

13.98

2620

<

£=§

1838

0

150

2117

14.11

+ 2070

1839

2

167

tl252

7.49

190

4500

23.68

30

1840

cl2

228

1942

8.61

143

3540

,24.40

50

5e

1841

c32

212

2475

11.62

146

8800

25.33

10

10 e

1842

30

250

3377

13.50

155

50

lOe

1843

{^13}
sl5

307

4725

15.39

166

3880

20.36

1844

270

4600

17.04

100

2500

25.

1845

s70

270

3600

13.38

100

1600

vl6.

1846

290

3000

1 10.34

140

3115

22.25

1847

s90

234

2571

u 10.99

144

5070

35.20

1848

s5

274

3544

12.98

150

4625

30.83

1849

s40

225

2600

X 11.55

170

5010

29.47

1850

8 90

321

4112

12.81

110

3150

28.64

1851

{ 825}

263

4420

16.81

118

3750

32.61

** After 1827, I ceased to keep a regular farm journal, as had been done
before. Hence tlie blanks in the table which appear afterwards to 1836.
The occupancy and direction of the present proprietor, Edmund RuflSin,
jr., began with the year 1839.

CROPS OE COGGINS POINT FARM. 185

Explanatory Remarks on the Land and its Management.

Quantity of land for cultivation (exclusive of waste parts), at first 472
acres ; increased by new clearings to 602 by 1826; to 652 in 1832 ; and no
more in 1842, though 80 more acres have since been cleared and tilled, be-
cause as much in 1836 converted to a permanent pasture. All the new
land added by clearing was poor, and very few acres of it would have pro-
duced more than 10 bushels of com, or 5 of wheat (without the marling),
after the 3 or 4 first crops. Of course the new land added served to reduce
instead of increasing the general average product per acre.

Rotation at first of three-shifts, viz. : 1 corn, 2 wheat on the richer half,
8 at rest, and after 1814 not grazed. This changed gradually to 4 shifts
(by 1823) of 1 corn, 2 wheat, 3 and 4 at rest. 1820, began to fallow for
wheat, in part and only in some years. In 1826 or 1827 began to sow the
wheat fields generally in clover, and about 1835, to fallow a part (say one-
fourth to one-third) of each clover field for wheat the year preceding the
crop of corn. This changed in 1 840 to a five-shift rotation, one-fifth of the
arable land being in corn, two-fifths in wheat (and oats), and two-fifths in
clover (or weeds), or other green or manuring crops.

The crops of wheat for first six years (1813 to 1818) raised on the richer
parts of each shift, making not much more than one-half the land only ;
the remainder being then much too poor to be sown. As these poorest parts
were marled, all were sown in wheat, in their turn. Therefore, the earlier
average products of wheat per acre as stated, were for the richer part of
the land, while since 1822 the average is for the worst as well as the best
land of each shift.

Grazing the clover fields commenced partially about 1830, and increased
since. Latterly about 20 head of cattle and 100 of hogs on the clover
during the grazing season.

The crops of hay, corn-fodder, &c., being all consumed on the farm,
their products have not been estimated.

Notes on Particular Crops, ^c.

a 1818 to 1822, inclusive, 27 acres of rich embanked marsh in com every
year, which served to increase these crops, and their average — which land
sunk too low after 1823 for corn, and has since been under the tide.

fin 1818, the first marling.

1828, oats on 17 acres.

1826 to 1830, a succession of bad seasons for wheat, or of crops — ^made
much worse (as I afterwards believed), by the land having been so long
kept from being grazed and trodden by cattle.

* These crops not actually measured, but amounts otherwise estimated.
All other quantities measured, unless stated otherwise.

I The richer half of the shift only cultivated in corn this year (1821).

§§ Marling nearly extended over all the cleared arable land requiring it,
and injurious where too thick.

From 1825 to 1830 inclusive, the richest land of the farm kept under
cotton, which served greatly to lessen the general products, and still more
the average product per acre of the wheat crops, during that time. Also,
fallowing for wheat had ceased (the suitable land being occupied by cotton),
and this had served still more to reduce the crops of wheat. The largest
crops of wheat raised previously (1819 to 1825) were' partly owing to the
crop being in part raised on summer fallow. And though this was in ad-
vance of having the all-important aid of clover, as green manure, still
wheat on fallow always produced much better than would the same land if
in wheat after corn, as usual. My first largely increased crop of wheat
16*

186 CROPS OP COGGINS POINT FARM.

(in 1822), was in part owing to the fallow process on a large space. But
as the same land had been then marled, and this was its first wheat crop
after the marling, I incorrectly ascribed all the great improvement of produc-
tion to the new fertility caused by marling. In after time, when the same
field yielded a much lighter crop of wheat, following -corn, there was great
disappointment, for the supposed diminished fertility. In truth, there was
great improvement of fertility at first, from marling, and no diminution
afterwards. But a still greater measure of temporary production was
superadded at first by the fallow preparation — which increase ceased when
this kind of preparation was not used. So generally now is known this
superiority of the yield of fallow wheat, that no farmer could be deceived
in this respect. Nevertheless, not only was I so deceived formerly, in the
beginning and partial use of summer fallow, but most other persons were
as ill-informed. For nearly all other improving farmers, in addition to
whatever means of fertilization they employed, soon also began to fallow
for wheat, and on clover, if the land had been enabled to bring clover.
The first and all succeeding crops so prepared for, would be more than
double any made previously on the same land, in the formerly universal
course, after corn. And this more than doubled production of the next
succeeding crop, when published, was supposed by all to be the result of a
doubled degree of fertility so quickly induced. Several such reports ap-
peared from different and excellent improving farmers in the "Farmers'
Register;" and great as were the actual measures of new fertility in all
these cases, it is certain that the writers of these reports, as well as the
readers, were deceived by the then new and little known peculiar benefits
of the summer fallow preparation for wheat — and consequently ascribing
less benefit to the mode of tillage, and more to the newly created fertility
of the field, than was proper. It was not until about 1835 that fallow pre-
paration had become my annual procedure, even to small extent ; nor un-
til 1839 that it was made a regular part of the rotation, extending to one-
fifth of the farm each year. Afterwards, as will be seen, the crops of wheat
were greatly and permanently increased over the general former products ;
they then having all the before produced fertility, caused by marling, to-
gether with the surface under wheat being extended to two-fifths of the
land, and half of that quantity of fallow preparation, and with clover, So
far as this manuring crop could be made to grow.

II 13,027 lbs. of cotton, net weight as sold, or 170 lbs. to the acre.

e 1836, the wheat crop nearly destroyed by rust, as was general through
eastern Virginia.

t Corn crop of 1838 and wheat crop of 1839 very much lessened by the
ravages of the chinch-bug.

c c On 26 of these acres the marling was a second application.

e The root crops (turnips and beets), and pumpkins and cymlings, occu-
pied part of the most highly enriched land — all consumed on the farm, and
products not estimated.

s s s Second dressings of marl, at about 250 bushels the acre ; applied
where first dressings had been lightest, or where more seemed to be wanting.

V Severe drought in 1845 cut short the corn crop.

t Remarkable wet time for harvest in 1846, and much loss of wheat.

u In 1847, much Hessian fly in wheat.

^ In 1849, three freezing nights in April cut down all the forward wheat.

In 1844, mj residence and labours were removed to the farm,
Marlbourne, in Hanover, wliich had been recently bought, and

FARMING ON MARLBOURNE. 187

wliicli I then began to marl, and to cultivate. I here brought to
bear much experience, and also judgment, both of which had been
wanting to my first marling labours, and therefore I now had more
speedy and complete success. Still there were important counter-
vailing obstacles, in the great existing diiferences of the soil and
level of my new farm, from the hilly lands on which my earlier
labours had been bestowed. Owing to my want of knowing the
peculiar requisitions for land entirely new to me, each field had
to pass once at least .through its course of culture, before I learned,
from my errors, what should be its proper tillage and management.
The arable land of Marlbourne, about 750 acres, was nearly all of
Pamunkey flats of high level, or "second low-grounds. '^ The
surface generally is so level and also so much of it in shallow
basin-shaped depressions, as to need much labour and judgment in
draining; the soils of all shades of texture between very sandy
and light, and very stiff and intractable, under tillage. The origi-
nal qualities had varied between rich and less than medium fertility.
The cultivation had been very exhausting ; all the land (not too
wet to cultivate), had been greatly reduced ; and much of it was_
extremely poor. About 80 acres, in many separated spots, of
cleared land, had been the bottoms of formerly existing ponds.
These " black-lands'' only still were rich, and also of very stiff soil.
Most of the other clay lands were the poorest of the farm, and
extremely poor. The sandy soils all bore sorrel, thus giving evi-
dence of their then acid condition. About 60 acres had been
marled, but quite insufficiently, and required full as much more marl
as had been laid on. All the remaining land had to be marled for
the first time. Of the procedure and the results, this occasion per-
mits only the general statement which will follow, of the quantities
of marl carried out (obtained from an adjacent farm), and the crops
made. It is understood that no previous crop of wheat, made ou
the farm for many years before my occupancy, had reached the
amount of 1000 bushels ; and even my first crop (reaped in the
second year) was increased by being partly on land I had marled,
and also by having an over-proportion of the richest ground,-takeu
in detached spots.

188

CROPS OF MARLBOURNE.

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PROFITS OF MARLING. 189

[1832.] "With all the increase of products that I have ascribed
to marling, the heaviest amounts stated may appear inconsiderable
to farmers who till soils more favoured by nature. Corn yielding
twenty -five or thirty bushels to the acre, is doubled by many natural
soils in the western states; and ten or twelve bushels of wheat
(following corn) will still less compare with the product of the
best lime-stone clay land. The cultivators of our poor region, how-
ever, know that such products, without any future increase, would
be a prodigious addition to their present gains. Still it is doubtful
whether these rewards are sufficiently high to tempt many of my
countrymen speedily to accept them. The opinions of many
farmers have been so long fixed, and their habits are so uniform
and unvarying, that it is difficult to excite them to adopt any new
plan of improvement, except by promises of profits so great that an
uncommon share of credulity would be necessary to expect their
fulfilment. The net profits of marling, if estimated at twenty or
even fifty per cent, per annum, on the expense, for ever — or the
assurance, by good evidence, of doubling the crops of a farm in teu
years or less — will scarcely attract the attention of those who would
embrace, without any scrutiny, the most absurd plan that promised
five times as much. Hall's scheme for cultivating corn was a
stimulus exactly suited to their lethargic state ; and that imprudent
Irish impostor found many steady old-fashioned farmers who had
always eschewed experiments, and held "book-farming'' in utter con-
tempt, willing to pay for his pretended patent-right and directions
for making five hundred barrels of corn without ploughing, and with
the hand labour of two men only.

The products and profits derived from the use of marl, as pre-
sented in the preceding pages, considerable as they are, have been
kept down, or lessened in amount, by my then want of experience,
and ignorance of the danger of injudicious applications. My errors
may at least enable others to avoid similar losses, and thereby to
reach equal profits with half the expense of time and labour. But
are we to consider even the greatest known increase of product that
has been ^et gained, in a few years after marling, as showing the
full amount of improvement and profit to be derived ? Certainly
not; and if we may venture to leave the sure ground of practical
experience, and lobk forward to what is promised by the theory of
the operation of calcareous manures, we must anticipate future
crops far exceeding what have yet been obtained. To this, the ready
objection may be opposed, that the sandiness of the greater part of
our lands will always prevent their being raised to a high state of
productiveness — and, particularly, that no care or improvement
can make heavy crops of wheat on such soils. This very general
opinion is far from being correct ; and as the error is important, it

190 VALUE OP SANDY SOILS.

may be useful to offer some evidence in support of the great value
to which sandy soils may arrive.

We are so accustomed to find sandy soils poor, that it is difficult
for us to connect with them the idea of fertility, and still less of
durability. Yet British agriculturists, who were acquainted with
clays and clay loams of as great value, and as well managed under
tillage, as any in the world, speak in still higher terms of certain
soils which are even more sandy than most of ours. For example
— " Rich sandy soils, however," says Sir John Sinclair, ^^ such as
those of Frodsham in Cheshire, are invaluable. They are cultivated
at a moderate expense ; and at all times have a dry soundness,
accompanied by moisture, which secures exellent crops, even in the
driest summers."* Robert Brown (one of the very few who have
deserved the character of being both able writers and successful
practical cultivators) says — "Perhaps a true sandy loam, incumbent
on a sound sub-soil, is the most valuable of all soils. "f Arthur
Young, when describing the soils of France, in his agricultural
survey of that country, in several places speaks in the highest
terms of different bodies of light or sandy soils, of which the
following example, of the extensive district which he calls the plain
of the &aronne, will be enough to quote : " It is entered about
Creisensac, and improves all the way to Montauban and Toulouse,
where it is one of the finest bodies of fertile soil that can anywhere

be seen." " Through all this plain, wherever the soil is found

excellent, it consists usually of a deep mellow friable sandy loam,
with moisture sufficient for anything ; much of it is calcareous. "J
The soil of Belgium, so celebrated for its high improvement and
remarkable productiveness, is mostly sandy. The author last
quoted, in another work describes a body of land in the county of
Norfolk, as "one of the finest tracts that is anywhere to be

seen" '-a. fine, deep, mellow, putrid sandy loam, adhesive

enough to fear no drought, and friable enough to strain off super-
fluous moisture, so that all seasons suit it; from texture free to
work, and from chemical qualities sure to produce in luxuriance
whatever the industry of man commits to its friendly bosom." §
Mr. Coke, the great Norfolk farmer, made' on the average 24 bushels
of wheat to the acre, on an estate of as sandy soil as our South-
ampton (where probably a general average of two bushels could
not be obtained, if general wheat culture were attempted) — and
many other farms in Norfolk yielded much better wheat than Mr.
Coke's in 1804, when Young's survey was jnade. Several farms

* Code of Agriculture, p. 12.

f Brown's Treatise on Agriculture, p. 218, of "Agriculture" in Edin.
Ency.

X Young's Tour in France.

§ Young's Surrey of Norfolk, p. 4.

SHALLOW AND POOR SOILS. 191

averaged 36 bushels, and one of 40 is stated } and the general ave-
rage of the county was 24 bushels.* Yet the county of Norfolk was
formerly pronounced by Charles II. to be only fit " to cut up into
strips, to make roads of for the remainder of the kingdom'^ — and
that sportive description expressed strongly the sandy nature of the
soil, as well as its then state of poverty and utter worthlessness.

Because certain qualities of poor clay soils (particularly their
absorbent power) make them better than poor sands for producing
wheat, we most strangely attach a value to the stiffness and in-
tractability of the former. Yet if all the absorbent quality and
productive power of clay could be given to sand, surely the latfer
would be the more valuable in proportion to its being friable and
easy to cultivate. The causes of all the valuable qualities and pro-
ductive power of the rich sands that have been referred to, are
only calcareous and putrescent manures, and depth of soil ; and if
the same means can be used, our now poor sands may also be made
as productive and valuable. I do not mean to assert that the most
highly improved sandy soils can produce as much wheat as the best
clay soils ; but they will not fall so far short as to prevent their
being the more valuable lands, for wheat as well as other crops, on
account of their being more easily cultivated, and less liable to suffer
from bad seasons, or bad management.

The greatest objection to the poor sandy lands of lower Virginia, as
subjects for improvement by calcareous manures, is not their excess
of sand, nor yet their poverty — great as may be both these dis-
advantages— but it is the shallowness of the poor and sandy soil.
The natural soil of a large portion of these lands, before cultivation,
is not more than from one to two inches deep, lying on a barren
sub-soil of sand. Now suppose this very shallow soil to be doubled
or even tripled in fertility by marling, or a productive power of 6
or 9 bushels of corn be raised to 18 bushels, still it would be but
mean land. And a long succession of annual vegetable covers to
be left on the land, or a great quantity of prepared putrescent
manure furnished at once, would be required to make such soil both
rich and deep. If the original soil had been ten inches deep, the
fertility before marling might have been but little more than on the
shallowest soil. But heavy marling and deep and good tillage
would have served speedily to make a rich and productive soil,
approaching in value to those rich sands of Europe mentioned
above.

Another large class of the poor lands of lower Virginia are the
close stiff clays, of which the soil is still more shallow than the
sands. Such land was described at page 124 and formed the sub-
jects of experiments 5, 6, and 7. This is the very worst soil known

* Young's Survey of Norfolk, p. 300 to 304.

192 RATES OP INCREASE OP MARLED CROPS.

before being marled, and also the most worthless of all L'nown
marled soils. And yet a three-fold product has been usually ob-
tained on these lands by marling alone, within four or at, most eight
years after the application of marl. Still, this land, as well as the
most sandy, wants only greater depth of soil and abundance of
vegetable matter, to become fertile and valuable.

While then calcareous manures may be counted on to produce
great improvement on all soils not naturally provided with them —
and to show a greater percentage of increase on the worst than on
be^er soils, and a remunerating profit on all ( — except those few
already calcareous — ) still, it will be far more profitable to marl
some soils than others. Dung, or other alimentary manure in the
best condition for use, increases vegetation nearly in proportion to
the quantity of the manure, and without regard or proportion to the
previous product of the soil. Thus, a wasteful application of dung
might, in a single year, increase the production of an acre of very
poor land, from 5 bushels to 50 bushels of corn. But calcareous
manures improve production somewhat in proportion to the previous
power of the soil; and if the original product was very low, the
addition thereto of 100 or even 200 per cent., made on the first
crops after marling, will show still but a poor product. These re-
remarks and illustrations are designed for the instruction of those
beginners who deem it important to learn on what kinds of soil to
apply their marl. In more general terms I would answer, ^^ apply
it to all soils not already calcareous ;" for however difi"erent may be
the measure of profit, I have never known marl applied unprofitably
in regard to place, if applied judiciously in manner. Of course I
refer to soils having some previous productive power and some
tenacity; and not to such naked sands, drifting with the winds,
as are seen in parts of North Carolina, South Carolina, and Georgia.

CHAPTER XXII.

THE EXTENT OF DURATION OF THE EFFECTS OP CALCAREOUS
MANURES.

Proposition 5 — continued.

In advance of the discussion of the general question of the per-
manency of calcareous manures, I will here state the facts in regard
to duration of effects observed and known of my own oldest prac-
tice. This extent of experience is indeed much too short to be
considered as the slightest evidence of such permanency of effect aa

CONTINUED EFFECTS OF MARL. 193

I ascribe to, and shall claim for, calcareous manures; nor are these
facts presented for that purpose. Still, even this comparatively short
experience shows an undiminished duration of benefit from calx-
ing, which is long compared to that of any other manuring. And,
therefore, for practical instruction, these and other like facts, if
brought from other sources, may be of more- use than any reason-
ing upon theoretical grounds, though going to prove a degree of
duration of calcareous manures immeasurably greater than any ex-
perience of man.

At this time of my writing (1852), thirty-four years have
passed since my first application of marl (in January 1818), and
which was the beginning of regular and continued labours in the
same way. The dressings given in 1818, and also in 1819, were
all very light ; and were soon inferred to be insufficient, even for
the immediate wants of the land. Therefore, more marl was added
to all these places, with the next succeeding tillage crop. This
early repetition prevented any observation of the oldest dressings,
as to their separate and continued eflfects. In 1820, my error as
to quantity was in the opposite extreme, the marl being then laid
on so heavily as to produce injury to the crops, after some years.
For these difierent reasons, the marling for the corn of 1821 is the
oldest of my applications which was both heavy enough, and not
so excessive as to cause any subsequent abatement (by disease) of
the increase of crops produced in the first few years. No second,
marling has there been given. The crops were increased always
in the first year after the marling ; and continued to show more and
more increase for ten or more years afterwards. Nor has there
been any known diminution of the highest productive power thus
obtained, to this time, in thirty-one years of tillage and rest, ac-
cording to the rotations in use, since the first marling. These re-
marks apply especially and strictly to the eleven acres of newly
cleared (and then poor and acid) land, forming the subject of ex-
periment 1 (page 117 of this edition) ; and the like results,
though for different shorter times, have been experienced on the
adjoining and similar land, subsequently cleared and marled,
to the amount of eighty or ninety acres. Of nearly all the other
lands, also marled, on Coggins farm, for crops of 1821, or soon
after, of different soils and conditions, the same statements should
be made, in respect to there having been no known abatement of
the early increase of crops. To this general rule there are two
limited exceptions, apparent or real. The first has just been ad-
verted to, and was before described at length (p. 155). This injury,
by disease, however great, was not at all a diminution of effect of
the marl, but the result of excess of quantity, and of improper
effect. With time, and supplying vegetable matter in proportion,
17

194 CONTINUED EFFECTS OF MARL.

tliis excess of marl has been moderated in effect ; and tbose appli-
cations now, as the others, show continuing good effects only. The
other exception, though not yet well understood, seems more real.
It applies only to some small spaces of land, sometimes slightly
oozy, on clay sub-soil. The surface of these spots is generally slop-
ing, though, in some cases, too level to lose much soil by washing
rains. The soil is shallow, and receives the excess of filtrating rain-
water from the more level and higher land, in wet seasons, and
which is discharged over its surface, when most abundant ; or other-
wise beneath the shallow soil, to the lower grounds, or to streams.
Such spots, being too wet only in winter and spring, and of small
extent, were either not drained at all, or, where covered drains had
been made and had failed, they were not renewed. In land of
this kind, it seems as if the oozing water dissolves and carries off'
the organic and nutritive ingredients of the soil. All soil of this
character, on the farm named, together makes but some ten or
twelve acres, in many small, irregular-shaped spots, and always of
small value for tillage, which circumstances caused their being neg-
lected. In all such cases, and even after being marled, and an
early improvement being thereby produced, these spots have become
more poor, and the soil itself seeming to diminish in quantity, as
if lost by being washed away, which, however, is not the case.
Previous and proper drainage would, no doubt, have prevented the
existence of this only known real exception to the continued and
unabated good effect of marling. It is stated here thus particularly,
not only as due to truth, but also because the facts will be again
referred to, in another connexion.

It should be observed, as to my general practice, and in regard
to all land referred to on which no repetition of the first marling
of early date has been made, or has been needed — and where no
abatement of the highest productive power has occurred — that the
following conditions existed, and were (as I suppose) essential for
the results stated : The marling had been heavy (perhaps furnish-
ing 1| to 2 per cent, of carbonate of lime to the tilled layer of soil),
and the land subsequently kept under sujBiciently mild cropping
and treatment, which allowed it to be supplied, through its own
growth of grass, and by help of atmospheric influences, with more
organic or nutritive matter than the cultivated crops took away.
On some marled land, on other farms, where the general course, of
cultivation was exhausting, and not compensated by enough of
natural or other supplies of vegetable and alimentary matter, the
early increase of product has been subsequently lowered. In some
such cases, within my observation, of most scourging tillage, in
eight or ten years after marling, and after excellent early effects,
the land was reduced to as low a state as before being marled.

RE-MARLINGS. 195

Such results, to this extent, have occurred only where the temporary
occupants of the land thought they had no interest in preserving
fertility for future use, or otherwise were grossly ignorant or neg-
lectful of their own interests.

But though the first dressing of marl being heavy, and not sub-
sequently repeated, 5re conditions best suited for showing the long
duration of efi'ects, that course is not economical or proper in any
other respect. When a heavy dressing is applied at once, perhaps
half the amount (even if not afterwards hurtful by its excess) is
superfluous, and lies useless and as dead capital for ten or twenty
years. It would be far cheaper, and more conformable to the
theoretical views of the action of calcareous manures, if half the
quantity of such heavy first applications had been withheld until
the addition was required by the increased store of organic matter
in the ^oil, and by the prospective continued supply, which would
call for more calcareous matter, for the purpose of combining with
what otherwise would be a useless and wasting excess of vegetable
or other organic matter.

Except where the first dressing was very light, and therefore was
very soon after added to, there were no re-marlings on the Coggins
farm until about 1843. The want of more calcareous matter then
seemed to be indicated on parts of the farm, which either had at
first been the least heavily covered, or otherwise had since received
the most putrescent manure from the stock pens, or other supplies
of vegetable matter. These indications were understood when,
after a long time, scattering plants of sorrel began to reappear ;
when there was evidence of great increase of organic matter in the
soil shown by the larger products of grain ; and never by any de-
crease of production, except of clover alone. Believing that it was
time for re-marling to be beneficial, that operation was then begun,
and has been continued annually since on the parts of the land
supposed to require it, on each field, preceding its next corn crop.
The soils so re-marled, of course, were neutral before (from the
first marling); or, at most, had very little excess of newly-formed
acid } and, of course, no perceptible or manifest benefit from the
re-marling was expected, or has been found, in the next succeeding
grain crops.

In these cases, the want of additional calcareous matter was not
caused by the waste or disappearance of the first supply ; but be-
cause the first supply, still remaining with very slight diminution
of quantity, and none of effect, had served so to increase the organic
matter of the soil, that a larger quantity of calcareous matter could
be put to use and profit. This is altogether diff"erent from the
supposed exhaustion, by use and by waste, of the first supply of
calcareous matter, as occurs of putrescent manure, and the conse-
quent necessity for replacing it by a new supply. And this latter

196 QUESTION OF DURATION OF CALXING.

is the cause requiring second and repeated applications of lime or
marl, as generally and erroneously supposed to operate, not only
by the ignorant, but by the scientific authorities whose opinions I
shall presently notice, and endeavour to controvert.

So far, I have merely aimed to show, by facts and from experi-
ence, that the increased productiveness of soiFs, induced by calca-
reous manures, has not ceased, nor, in general, been at all diminished
within such short time of experience as belongs to the agriculture
of this country, and of which only we can know and estimate all
the conditions and circumstances. But, however important may
be the value of these evidences of durable .efi"ect, bearing on the
question of the profit of practical operations, they go but little way
towards fixing the limit of duration, and of the undiminished ope-
ration of calcareous manures.

In the first sketch of this essay, published in 1821, as well as in
all the subsequent editions, I asserted and argued for the absolute
permanency of calcareous earth, acting as manure in soil ; and the
remaining in the soil of the lime, with but very little appreciable
diminution of its quantity, through all its chemical changes and
different successive combinations. In this opinion I have found
myself opposed to nearly if not quite all known authorities, whether
of scientific writers, or the practical European cultivators whose
reported practices and results have been quoted as evidence. Under
such circumstances, it was proper that my grounds should be care-
fully reconsidered, in connexion with the opposing reasoning. This
has been done ; and while deeming it proper to yield something of
the breadth of my previous position to newer and better information,
and while ready to admit the previous errors, and their recent cor-
rection, I have still to maintain my former opinion in its most
important points. And, without exception, I deny the counter
opinions, either asserted by authors of high reputation, or neces-
sary deductions from their assertions, viz. : that calcareous manures,
though long continuing in soils, still are liable to be nearly exhausted
by waste and use in terms of say twenty or thirty years ; and that
they then require being replaced, and may be so repeated, profitably,
and without limitation of the number.

No calcareous manurings made by man can possibly be old enough,
or capable of being clearly enough traced through their actual pro-
gress, to afford evidence of even very long duration, much less en-
tire permanency of effect. But, however weak for this purpose,
Buch facts, of long abiding effects, will at least serve to rebut the
assertions of the much earlier and necessary cessation of all the
effects of lime. For such opposition even my own experience of un-
abated effects, from applications not repeated, now extends to thirty-
one years. Another much older application (stated at page 114),
after long neglect, and under the worst treatment for its operation,

- BRITISH OPINIONS OF LIMING. 197

showed visible effects at the end of sixty years. Lord Karnes men-
tions a particular case of the continued beneficial effects of an ap-
plication of calcareous manure for one hundred and twenty years
(Grentleman Farmer, p. 266, Edin. Ed.), and even Professor John-
ston, whose reasoning I shall have mainly to oppose, quotes, with
apparent assent, the opinion of "an intelligent and experienced
farmer," that certain lands in Scotland "would never forget an
application of forty to sixty bushels of lime to the acre."

I shall take from the Lectures of Professor Johnston, the argu-
ment in support of the temporary continuance and operation of
lime in soils, and its final entire loss and disappearance. No more
able advocate of the opinions I shall oppose, nor one of higher au-
thority, could be presented. His observations on lime as manure
are the most recent, and fullest of any known ; and in most of the
points, his opinions command my approval. In regard to this
branch of the subject, his views are as follows : —

"A certain proportion of lime," says this author, "is indispensable
in our climate to the production of the greatest possible fertility.
Let us suppose a soil to be wholly destitute of lime — the first step
of the improver would be to add this indispensable proportion.
This would necessarily be a large quantity ; and therefore, to land
limed for the first time, theory indicates the propriety of giving a
large dose. Every year, however, a certain variable proportion of
the lime is removed from the soil by natural causes. The effect of
the removal in a few years becomes sensibly apparent in the di-
minished productiveness of the land. After a lapse of five or six
years, during which it has been gradually mixing with the soil,
the beneficial effects of the lime are generally the most striking ;
after this, they gradually lessen, till, at the end of a longer or short-
er period, the land reverts to its original condition ''(^. 383, 384.)
He states the usage in Roxburgh (Scotland), where most lands
are leased for nineteen or twenty-one years. On entering upon a
farm, the new tenant begins with applying 240 to 800 bushels of
[unslaked] quick-lime to the acre, and continues equal progress
with his rotation of tillage, until all the farm is limed, within the
time of four or five years. He then continues to crop without more
liming for fourteen or sixteen years ; when, if he is sure of remain-
ing on his farm for another lease, he begins to lime again, at the
same rate as before. * The author speaks of no limit to these re-
peated heavy limings ; and therefore it may be fairly inferred, that
he considers the repetitions, and the alternations of full supply and
disappearance of the lime, to be indefinite, or that at no future time
will such repetitions of liming cease to be required. Indeed, such
inference is unavoidable, if his previous statement be correct, that
land " reverts to its original condition," of being " wholly destitute
of lime." In such case, the land certainly would as much need
17*

•198 RE-LIMING IN BRITAIN.

lime again, as if it had never been applied before. Elsewhere this
author speaks of twenty years as the ordinary duration of heavy
limings; and that in some cases, on grass land, the effect lasted
thirty years, (p. 396.) ''A heavy marling or chalking in the south-
ern and midland counties of England is said to last for thirty years,
and the same period is assigned for the sensible effects of the ordi-
nary doses of lime-sand in Ireland, and 9i shell-sands and marls in
several parts of France/' (p. 396, 397.)

There is no subject of practical agriculture on which it is more
difficult to gather truth from the evidence of alleged facts than in
regard to applications of calcareous manures, made by persons hav-
ing no knowledge or conception of their true action. The " facts',''
as understood and repiorted by the most truthful men, may be de-
ceptions, and lead to false conclusions. There is a general accord-
ance in the practices of the re-limings, as above described, and the
- repetitions of my own early marlings — yet how different in the
causes supposed in the two cases ! The British re-limings are re-
quired because the first dose was supposed to be either nearly or
entirely gone, " and the land had reverted to its original condition,
destitute of lime." In the other case, the lime certainly still re-
mained in quantity, and was believed to be not appreciably lessened ;
but more was required to balance and combine with the increased
organic matter. Besides these two causes, supposed and real, for
land needing re-liming, it may be wanting, and more than one re-
petition, because the previous dose was much too small for the
then wants of the soil. And in numerous cases, when no need
truly exists for more lime, and when indeed the land has been
already limed too heavily for its condition, but is exhausted of ils
organic matter, and thereby impoverished by severe tillage, still
more lime is sometimes ignorantly added, and uselessly for its
resuscitation, if not injuriously. Yet all these different cases of
proper and improper applications, would be confounded by ordi-
nary report. And all that we can be sure of from such facts
reported to and published by Prof. Johnston, is that re-limings, at
intervals of twenty or more years, are common in Britain ; and
that sometimes, or generally, they have done good, and sometimes
harm. The statements of experience rarely extend so far as to
include the third or fourth application. When these shall be
known, I predict that there will be found many cases in which the
last application is in excess, and will do more harm than good.
Yet, strictly in accordance with the views of Prof. Johnston, the
fourth or the hundredth application, after proper intervals, would
be as much needed, and therefore should be as beneficial as the
first.

So much for the facts, and the very imperfect knowledge we can

SUPPOSED REMOVAL OF LIME FROM SOILS«

199

have of tliem. I proceed to quote the author's explanations of the
manner in which he infers that the lime is lost to the land.

1. "A considerable quantity of lime/^ he says, '^ is annually
removed from the soil by the crops reaped from it. We have
already seen (Lecture X., § 4, p. 221) that in a four-years' rota-
tion of alternate green and corn crops, the quantity of lime contained
in the average produce of good land amounts to 149 lbs.* This is
equal to 37.5 lbs. of quick-lime, or 67 lbs. of carbonate of lime,
[per acre] for each year. The whole, however, is not usually lost
to the land. Part, at least, is restored in the manure, into which
a large portion of the produce is usually converted. Yet a con-
siderable portion is always lost — escaping chiefly in the liquid
manure and drainings of dung-heaps." (p. 399.)

Answer. — To some extent, the loss of lime to soil, by being ta-
ken up into the crops, is certain ; and I always before admitted it
expressly. But, on the author's own showing, the quantity lost in
this manner is very much smaller than would appear from the
above statement, if received without examination. The table
given previously in the '^ Lectures,'^ and referred to above, of the
amounts of various inorganic matters abstracted from the soil by
all the crops of the ordinary Norfolk rotation, in four years, shows
the following amounts of lime so lost per acre : —

1st Year, Turnips (25 tons of roots), contains
in roots and leaves
f Barley (38 bushels), grain,
\ Straw of same,
/ Clover, 1 ton of hay,
\ Rye grass, 1 ton, .
( Wheat, (25 bushels), grain,
1 Straw of same,

2d Year,
3d Year,
4th Year,

lbs. Lime. Lime. Total.

45.8

12

63.0
16.5

7.2

lbs. 145.4 4-3.C

2.1

:149

By my thus presenting separately the respective quantities of
lime taken up by the grain alone, barley and wheat, which may be
supposed to be mostly sold and removed from the farm, and of the
turnips, hay, and straw, which mostly are consumed on the farm,
and the lime in them again returned to the fields somewhere in
the manure, it appears that the total loss of pure lime per acre, in
four year's, by removal from the farm in the grain crops, is only
3.6 lbs. ; and annually, the average (0.9 lbs.) less than 1 lb. per

* This is stated as 248 lbs., and the numbers following in proportion.
But it is manifestly by mistake, as is seen by the table referred to (in
Lect. X.), and by which I have corrected the sums above. The difference,
however, does not materially aflfect the argument or conclusion. E. B.

200 LIME TAKEN UP BY CROPS.

acre. And if the lime abstracted by the retained straw and other
home-consumed crops be added as lost, unfair and incorrect as
would be that assumption, the whole annual loss would be but
37.25 Ib^. of lime, or say about one bushel of quick an^ slaked lime.
If then, 300 bushels of quick-lime had been applied, or as much
lime in marl, it would require the total removal of 300 successive
crops (and as heavy crops as those above stated) to take away
the lime applied. If considering only the loss of lime in the
grain, that annual waste, of less than a pound per acre, would re-
quire 11,175 successive and as heavy crops for the complete using
of the lime applied. In the one case or the other, these respect-
ive quantities of lime, annually resupplied to the land, would be
enough to compensate for the supposed waste. If the barn-yard
and other organic manures of the farm were all saved and applied
in time regularly to every part of the fields, then less than a pound
of lime added thereto for each acre, annually, would restore the
"whole amount lost in the sold and removed crops. This is very
much less than I had before supposed, and admitted, from more
imperfect information than that now furnished by Prof. Johnston.
Boussingault reports, among other results of his many analyses,
the mineral, or inorganic parts composing the ashes of samples of
all the crops of his five-field rotation at Bechelbronn, which was
referred to above, for a diff'erent purpose. The amount of each
crop to the acre, throughout the rotation, had been ascertained.
And having, by analysis, determined the constituent elementary
parts of a certain quantity of each product, calculation correctly
showed the respective quantities of these constituent parts, in the
crops of each year, and for the whole rotation of five years. I
will extract below, from two of his tables, the statements of the
j^verage crops and these inorganic parts, which were taken up, and may
ibe supposed were as much of these matters as the crops required.
There was an abundance of these matters in the soil ; for, besides
the natural original supply in the manure for the rotation, there
was furnished, of each inorganic matter, more than all that the
crops took up. Of the lime, this supply in the manure was more
than quadruple the quantity taken up.

ALLEGED REMOVAL OP LIME BY WATER.

201

^^

Acids.

S3

^«

, ■

aj

d

'o

AVERAGE CROP PER ACRE, ON

^•9

i

'i

GQ

d

THJb! FIVE FIELDS OF THE

Lbs.

^ § c^

o C

, 6

^

.9

&)

=!<3

■-§

ROTATION.

II 2

p.

-^
O

s

1

58

0

1. Potatoes,

11,733

lbs.113

13

8

3

2

6

2. Wheat, lbs. 1231, \
4. Wheat, lbs. 1521, /

2,752

50

24

1

8

15

Wheat straw, of same, \
2798, 3456, /

6,254

358

11

4

2

30

18

34

242

3. Clover hay, .

4,675

284

18

7

7

70

18

77

15

5. Oats,

1,232

89

6

1

3

5

20

Oat straw of same, .

1,650

60

If

^

3

5

n

17

24

Turnips, secondary crop, "(
after wheat of 4th year, /

8,754

50

3

5

1

6

2

19

3

According to this statement, during the rotation of five years,
the total amount of pure lime taken up by the potato crop, and
three grain crops, was 4 lbs. The turnips, straw, and clover, took
up 120 lbs. The former quantity, equal to the yearly average of
0.8 lbs., is all that may be supposed to be removed from the farm.
The latter, of 24 lbs. a year in the turnips, litter and hay, must be
returned to the farm in manure. Both these quantities are still less
than by the foregoing estimate, quoted by Johnston. Both are so
minute as scarcely to be appreciable; and all such loss would
scarce deserve consideration, as a practical matter, but for the false
importance which has been given to this manner of abstraction of
lime from land.

The ordinary farm-made manures, with some purchased peat-
ashes, composed the manure applied by Boussingault, in each ro-
tation ; and which served to supply to the soil much more of all
the mineral parts than were taken up by the crops of all kinds.
Of course, there could have been no deficiency of supply of lime
for the use of the growing plants, nor any less taken up by them
than they required.

2. Another waste of lime alleged by Prof. Johnston is by solu-
tion in rain (or other) water. lie says : " In the quick or caustic
state, lime is soluble in pure water, 750 lbs. of water serving to
dissolve 1 lb. of lime. The rains that fall cannot fail, as they sink
through the soil, to dissolve and carry away a portion of the lime
so long as it remains in the caustic state. Again, quick -lime,
mixed with the soil, speedily attracts carbonic acid, and in time
becomes the carbonate, which is nearly insoluble in pure water,
but is soluble in water impregnated with carbonic acid ; and as the
drops of rain in falling absorb this acid from the air, they become
capable, when they reach the soil, of dissolving an appreciable
quantity of the finely-divided carbonate of lime on cultivated fields.

g02 SUCH WASTE OP LIME DENIED.

Hence the water that flows from the drains upon such lands is'
always impregna,ted with lime, and sometimes to so great a degree
as to form calcareous deposits in the interior of the drains them-
selves. . . The loss of lime from these causes cannot be
estimated, and must vary with the exposure to rains, and slope of
surface, &c. But the cause is universal jind continually operating,
and would alone therefore render necessary, after the lapse of years,
the applications of new doses of lime/' (p. 399.)

Answer. — These several chemical powers, &c., are fully admitted.
But their action, under usual and proper conditions of limed or
marled land, must be very limited, even when any such agency of
waste can be produced. Caustic lime, as stated above, may be
sparingly dissolved in pure water. But lime, applied as manure,
does not long remain caustic, and, after ceasing to be so, is no
longer the least exposed to this particular source of loss ; and marl,
or carbonated lime, is not at all so exposed. As carbonate of lime,
however, and while so remaining, another means of solution is
operating, in the carbonic acid of the air. But the quantity of
this acid is so small, and its tendency to be absorbed by water so
great, that a very light rain, or merely the beginning of a long or
heavy rain, must bring all the then floating carbonic acid to the
soil. This fluid would immediately sink into the pores of the earth,
with its dissolved carbonate of lime, if any ; and there be preserved,
either mechanically or chemically (by further and speedy combina-
tion with other matters of the soil), so as to be very little if at all
subject to removal in superfluous water before being saved and put
to use as manure in later-formed and more fixed chemical combina-
tions. This particular source of waste cannot apply at all but to
lime in the form of carbonate. And, according to my previously
expressed views, that form is soon changed (with moderate and
proper dressings) to other salts of lime, or combinations with the
organic parts and the other earths of the soil. In such case, the
last considered outlet for waste is also closed ; but, possibly, and
as Prof. Johnston supposes certainly, others are opened, and will
operate, as thus : —

3. "During the decay of vegetable matter, and the decomposi-
tion of mineral compounds, which take place in the soil where lime
is present, new combinations are formed in variable quantities,
which are more soluble than the carbonate, and which therefore
hasten and facilitate this washing out of the lime by the action of
rains. Thus chloride of calcium, nitrate of lime, and gypsum, are
all produced — of which the two former are eminently soluble in
. water — while organic acids [as humic, acetic, &c. &c.] also result
from the decay of the organic matter, with some of which the lime
forms readily soluble compounds (salts), easily removed by water/'
(p. 399.)

OTHEK ALLEGED CAUSES OE WASTE. 203

Ansicer. — Admitted fully, as to the supposed chemical changes,
and the solubility of some of the new compounds. But these new-
compounds are produced only so long as the lime remains either
caustic or carbonated in the soil, neither of which conditions ex-
tends beyond a few years, if dressings be not excessively hea^,
and if the material is finely divided and well difi'used through the
soil ; and while in progress, the formation of these acid products,
and their resulting salts of lime, must be so extremely slow and
gradual, that probably nearly as fast as produced they are further
combined with other solid matters, and secured from the waste
which possibly might be caused by their solution in water. Of
course, it is impossible to estimate the measure of this supposed
saving process. The general effects are inferred from the known,
unquestionable, and grand results of thousands of years old, seen
in the still preserved constituents of lime and of fertilizing organic
matter in combination, in all the natural moderately calcareous an,fil
rich neutral soils known. If we were to admit the full operation
of causes of waste of lime, as supposed by Professor Johnston, then
every natural and moderately calcareous soil must long ago have
lost nearly or all its lime, by one or all of the several preceding
operations of solution and removal. And if deprived of the lime,
it would be a certain consequence (according to my views) that the
soluble and useful organic matter, however abundant, under ordi-
nary circumstances of soils, would also be carried off, leaving the
uncultivated land throughout the world destitute of both lime and
organic matter, and therefore completely and hopelessly barren.
Such results, or even any approaching thereto, are unknown; and
their possible existence is as much opposed to all known facts of
natural soils, as they would be to our belief in final causes and the
all-benevolent care and protection of his works and creatures by
Almighty Grod.

But however strong may be these general reasons for denying
the wasting of lime and its resulting salts, there is a particular
chemical power asserted by recent authority, which, if true, covers
and sustains nearly my whole ground of objection. Professor
G-ardner, in his late work, ^' The Farmer's Dictionary'^ (published
1846), in the article ^^ Humus,'' refers to, as a known and undis-
puted chemical truth, that the humate of lime is nearly insoluble
in water.* Now, though the humic acid is but one of four or five

^ Of the fact of the insolubility of humate of lime, the authority of Prof.
Gardner, or of any recent chemical writer, must be sufficient. But I would
deny his deduction from that property, that therefore humate of lime can-
not directly act to feed plants. Vegetable life can exert dissolving and
decomposing powers that the chemist in his laboratory cannot imitate or ap-.
proach. If the property of insolubility in pure water rendered any substance
necessarily useless as a direct manuring agent, we should be compelled

204 CAUSES OP WASTE CONSIDERED.

acids of soil, of vegetable origin, which, chemists have recently
ascertained, the humic acid is by far the most frequent, abundant,
and important of all. Of course when lime is applied to an acid
soil (i. e., any one needing the chemical action of calcareous earth),
tl* most abundant resulting salt will be the humate of lime, which
being insoluble in water (or very nearly so), is entirely secured
from the waste to which a soluble salt might possibly be, but is
not necessarily liable.

4. "The ultimate resolution of all vegetable matter in the soiF'
continues Professor Johnston, " into carbonic acid and water, like-
wise aids the removal of the lime. For if the soil be everywhere
impregnated with carbonic acid, the rain and spring waters that
flow through it will also become charged with this gas, and thus be
enabled to dissolve so much the larger portion of carbonate of lime.
Thus, theory indicates, what I believe experience confirms, that a
given qiiantity of lime will disappear the sooner from a field, the
more abundant the animal and vegetable matter it contains.'' (p.
899, 400.) — Ansiver. — First, to the last incidental passage, I will
merely state unqualified dissent. So far from the quantity of vege-
table matter promoting the escape of the lime, it would tend to
prevent such waste, if otherwise likely to occur. According to
my theory of the action, the lime and vegetable matter in soils
combine with each other, and with other parts of the soil, each one
thus serving to retain the others, if otherwise liable to waste.

Whatever may occur in old manure heaps, or in the chemist's
laboratory, it is not likely that much, if any, vegetable matter in
soil (and when not in great excess), can pass through all the va-
rious stages of decomposition, to the last, that of being resolved into
carbonic acid and water. Previous changes would slowly render
the parts soluble, and fit to be drawn up by the roots of plants ;
and probably all would be so used, so that very little reaches the
gaseous state. But if carbonic acid should be formed, the pro-
duction would be very slow, so that the results would be all required
for, and taken up, by plants in aid of their support and growth,
almost as fast as they were produced. Thus, there would be but
little if any opportunity for the alleged waste of lime^ in conse-
quence of the organic matters in the soil reaching the last stage
of decomposition, and being reduced to carbonic acid and water.

So far, the sundry particular reasons ofi"ered in support of the
alleged transitory operation and existence of lime in soils have been
opposed by particular objections. But still stronger grounds of
objection may be assumed in general views, which will now bo
brought forward.

to place in tlie same class both carbonate and phosphate of lime entirely ;
and also, caustic lime, for much the greater part of the bulk of on ordinary
application as manure.

DURATION OF EARTHY MANURES. 205

Most farmers are so accustomed to consider manures as being
fleeting in their operation and existence in soil, as are the ordinary
putrescent manures, that it is difficult for them to have any con-
ception of any kind lasting and acting for ever. And this difficulty
of conception, stands much in the way of my argument. But, how-
ever little used by farmers, or even thought of, in this light, it ig
obvious and undeniable, that certain mineral manures will continue
in operation, and without abatemient of effects, as long as the soil,
or the habitable globe itself, shall exist. Thus, clay is a manure
for sandy soil, serving to stiffen and compact its before too light,
loose, and open texture. Sand also is a manure for stiff clay soils,
serving to correct their tenacity when wet, and their obduracy when
dry, and make them more open, light, and permeable ; more easy
to cultivate, and more safe for production. And in either of these
manuring operations, it is self-evident, and not admitting of ques-
tion, that the continuance of these manures, and their good effects,
will be eternal.

Carbonate of lime in soil, whether supplied by nature or art,
like sand and clay, is a ponderous earth, and but to small extent
liable to waste or loss by any natural agency. It is insoluble by
water, except so far as water may contain carbonic acid, which
renders water a solvent of carbonate of lime. But this impregna-
tion of water in soil is very limited. It can scarcely occur at all
except in the usual mode, by rain-water, when descending through
the atmosphere, absorbing and bringing to the earth the very small
and strictly limited quantity of carbonic acid in the lower atmos-
phere. Except in this respect, and for the still more minute and
scarcely appreciable quantity of lime taken up by growing plants, (as
stated above), carbonate of lime in soil would seem to be as inde-
structible, and as surely abiding through all future time, as the clay
or the sand which might also have been given as manure, or other-
wise held as natural ingredients of the same soil. As rain-water
always brings to the earth some carbonic acid, though in extremely
small quantity, still, to that small extent, the carbonate of lime in
the soil is liable to be dissolved; and when so dissolved, if there
were no counteracting agencies, some of the dissolved earth might
be lost (possibly) by filtration through the soil, or, less improbably,
by being floated off from the surface, in the flowing away of any
excess of rain-water. But there are counteracting agencies ope-
rating to prevent the loss of lime in this, and also in other soluble
forms. According to my own early (and then unsupported) views
of the formation of acid in soil, as well as according to the now
received general opinions on that subject, the carbonate of lime
would soon begin to be changed to other salts of lime, by combina-
tion with other acids in the soil. Some one or more of these newly
formed salts might be much more soluble in water than the carbo-
18

206 DURATION OP SALTS OP LIME.

nate, and therefore more liable to be wasted by rain-water surcharg-
ing the soil. This result can neither be affirmed nor denied, from
any positive knowledge of such facts, or of the chemical changes
necessary for them. We do not know which of the vegetable acids,
nor how many of them, at once or successively, may combine with
the lime ; and therefore cannot know what other salts of lime will
be produced. The humate of lime, which, it may be presumed,
will be the most abundant of suchvproducts, is difficult of solution
by water. If oxalate of lime should be formed (as is probable,
where sorrel was before an abundant growth), that is an insoluble
salt, and therefore safe from this manner of loss. The acetate of
lime, another probable result, is easily soluble in water ; and per-
haps other vegetable and soluble salts may be formed in soils,
though more rarely and in less quantity than the humate and oxa-
late of lime. Besides, there are other soluble salts of lime named
by Prof. Johnston, and quoted above. But, however little may
be known by chemists or others of the kinds and quantities of these
salts into which carbonate of lime is gradually changed, by access of
different vegetable or other acids, it appears, from the general and
abiding effects on fertilization and production, that all these differ-
ent salts of lime continue to perform, and as fully, all the enduring
functions of carbonate of lime. For when a soil, after having been
made slightly calcareous, has in time become neutral (and of course
its carbonate of lime has been all converted to other salts of lime),
the soil thereby loses none of its so acquired fertility or value,
through any succeeding known time. This could not be the case
if the lime in its new condition was liable to certain and rapid, and
finally complete waste, by dissolving and escaping waters. In a
former chapter (pp. 96, 97,) I maintained that the serviceable and
acting lime in soil (for of course any quantity in excess is not so
considered) becomes chemically combined with the organic, or ali-
mentary manuring principles present, and all these with other earthy
parts of the soil. Judging from the abiding effects, and in regard
to neutral soils, it may be safely inferred that such combinations
occur not only with the carbonate, but with nearly all the later
produced salts of lime, resulting from the carbonate. And if so,
such combination with other insoluble and permanent matters of the
soil, would render as fixed and permanent even the salts most solu-
ble and liable to waste when alone. Of this, I will state an ex-
ample that will be familiar to every one. Sulphate of iron (copperas)
is easily soluble in water ; and, if alone, would be soon removed
completely by the dissolving water passing away. The red juico
of fresh nut-galls would be nearly as easily taken up, and washed
off by water. But these two substances, if meeting together, would
chemically combine, making ordinary black ink ; which cannot bo
washed away by water from any substance to which it is attached ;

NATURAL CALCAREOUS SOILS. 207

nor can either of the before soluble parts be thus taken from the
other. It is in this manner that lime, even in its soluble forms,
is fixed permanently in soils. And whether in this manner, or
otherwise, it is sufficiently manifest that such results are produced,
by reference to the great manuring operations of nature, unlimited
as to both space and time, and compared to which the largest ex-
perience and greatest labours of man are as nothing. To these great
operations I now appeal for proof of the long-abiding and unending
benefits of calcareous manures.

Soils naturally supplied with lime, in proper proportions, are as
much oases of calcareous manuring, as if performed as early by
agricultural art and industry. All such naturally limed lands,
throughout the known world, have always been, and still continue
to be, among the most valuable and fertile. Such lands, in Europe
and Asia, remarkable for their productiveness thousands of years
ago, have lost nothing of that character to this day. In America,
our agriculture is comparatively new, and therefore our historical
proofs of such facts are comparatively limited. But even in this
new country, the rich soils of the valley of Virginia have continued
to bring fine crops for more than a century. And no one acquaint-
ed with these and other similar naturally fertile lands has ever
doubted that they will, under judicious culture, and equal circum-
stances, maintain their present superiority over other poorer lands,
through all time. Yet these fine lands owe their value and supe-
riority to their natural lime constitution ; and their continued fer-
tility, for a century, is but the efi'ect and evidence of the original
liming having operated as long. It is true that many such lands,
in this country, have already been greatly reduced in fertility by
long-continued exhausting cultivation, which has been used to take
as much from, and return as little as possible to the soil. But
though such exhausting tillage is capable of consuming and destroy-
ing most of the organic matter, and thereby inducing comparative
. barrenness for the time, yet it does not lessen the lime ingredient
and quality, nor the recuperative powers which the soil derived
from the lime ; and which, if left again to act, for sufficient time,
will restore the former condition of productiveness. Scourged as
such soils have been in many cases, by continued exhausting til-
lage, they still show, in their most reduced and barren condition,
as much as ever before, the possession of the peculiar qualities de-
rived from their lime ingredient. When such soils, by time, or
cultivation, shall have lost their dark colour, their power of absorb-
ing and retaining moisture, and of retaining putrescent manures,
and their peculiar fitness for producing leguminous plants, then,
and not before, it may be asserted with some plausibility that the
salts of lime, which had formerly induced fertility, have been since
entirely lost by the soil.

208 ABSURDITY OF THE DOCTRINE OPPOSED.

If the lime in soil was indeed subject to waste and loss in the
manner and to the extent maintained by Prof. Johnston, the ill
consequences would necessarily be general, and so disastrous that
there could be no possible mistake of the operation and its results.
Upon his own premises, the actual (and always admitted) removal
of lime from the soil in its crops, though certain, is too small to
be appreciable. It is a theoretical truth, of which the practical
operation is imperceptible. And this imperceptible part of the
alleged loss of lime is all that is caused by tillage and the removal
of the crops. It is by the lime (either as quick-lime, carbonate, or
other salts) being dissolved in water, according to Prof. Johnston's
views, that the great loss is incurred, and that all, or nearly all,
the lime furnished for manure is finally lost, and within not very
long periods of time. This, the great cause of waste, is operating
(as asserted) by every considerable or excessive rain, on all soils
containing lime, and through all time. This operation, too, would
not be less sure on lime existing naturally in soils, than if supplied
as manure, and as thoroughly incorporated as in a natural calcare-
ous or neutral soil. And if twenty or thirty years' operation of
the solvent power of rain-water suffices (as asserted) usually to re-
move either mostly or completely the lime before furnished to the
land as manure, then, surely, the same universally operating power
of rain-water must as completely remove and utterly waste any
barely sufficient natural ingredient of lime, say in 100 years. So,
all lands throughout the world, moderately and properly supplied
by nature with lime, would thus have lost the whole thousands of
years ago. And they would all have thenceforward remained thus
destitute of lime, until being re-supplied by man. This kind of
artificial manuring has never been used on but a very small pro-
portion of all the lands of the world under tillage ; and even on such
small proportion, for but a short portion of all the time in which
tillage has been in use. Of course, then, on all other lands not
containing an excessive store of lime, the whole of this essential
ingredient, in every form of combination, should be entirely want-
ing ] and, therefore (according to my views of the absolute neces-
sity for, and the action of lime), much the greater portion of the
surface of the earth would have been thus rendered perfectly bar-
ren. For, without lime to combine with and fix organic matter,
there would be nothing to retain the latter; and the complete
waste of the lime would be necessarily followed by the waste of all the
enriching matter in the soil, and the inducing of complete sterility.
The known fact that no such eifects are produced, or any even ap-
proaching to them, is alone sufficient proof that the waste of lime
in soil cannot occur, as supposed by Prof. Johnston.

Enough has been said in opposition both to the alleged fact of
the natural waste of the acting and requisite lime in soil, and the

OTHER SALTS IN SOILS. 2W

supposed manner of the waste being produced. But there is an-
other connected and similar subject which deserves notice.

The salts of lime are not all the salts, nor the only soluble mat-
ters, usually present in soils. The inorganic parts of plants,
forming their ashes, after their being burnt, consist mostly of
various salts, not only of lime, but also of other bases, as magnesia,
potash, soda, &c. These salts, of course, were drawn by the plants
from the soils on which they grew. From their being universally
present in plants (so far as known), modern chemists have inferred
that all these various salts are essential to the health, if not to the
existence of the plants, and, of course, essential to the productive-
ness of the soil for these plants. But most or all of these salts, of
magnesia, potash, soda, &c., are soluble in water, and some very
easily soluble. If, then, as Prof. Johnston argues as to lime, water
necessarily dissolves and removes whatever soluble salt or earth is
existing in soils, I would ask why have not all these other soluble
matters been removed from all soils ? These are present usually
in much smaller proportions than lime or its salts, and therefore
could be more easily dissolved and removed. That no such com-
plete loss of these other salts has been produced in any soil, so far
as known, is another sufficient reason for inferring that neither ia
lime, nor its more soluble salts, likely to be taken away from the
Boil, when acting usefully as fertilizing matters, by the solvent
action of water. This view of the case is still stronger in another
aspect. Liming in England and Scotland is usually renewed (as
stated above), or requires renewal, in twenty years or thereabout.
The farmers of Norfolk (England) also renew their heavy marlings
every eight years or sooner. Hence it is argued that the calcareous
..manure is exhausted in some such limited times. But the other
salts, of magnesia, potash, soda, deemed by modern chemists as
essential to soils and to their production, are almost never replaced
"by artificial applications, or by design, even under the highest and
best farming, and absolutely never (unless by rare accident) in
ruder culture. Hence it would seem legitimately deduced from
Prof. Johnston's reasoning as to the disappearance of lime, that
even in the highly-limed and cultivated lands of Britain, the other
elements of fertile soil, all deemed as essential to production as
lime, ought to have been exhausted long ago. On nearly all other
parts of the world, not only all these other substances, but also the
lime itself, ought to have been entirely removed, and every soil
rendered barren. This reduction to an absurd conclusion would
alone be enough to disprove the argument I oppose.

Prof. Johnston, in his attempt to prove the transitory existence

and operation of lime as manure, has committed an error to which

scientific men who treat on practical agriculture are extremely

prone. This is to suppose that matters ia the soil act with and

18*

210 THE MEASURE OP DURATION.

are acted on by others present, as they would in the chemist's
laboratory. In the soil, there are many other matters present, and
some, perhaps, whose presence is not suspected ; and very complex
and extensive and varying combinations may exist of various mat-
ters, whose characters and powers are certainly not understood.
But while denying the correctness of his application to the soil of
correct and unquestioned chemical laws in regard to the known
matters and agencies under consideration, and while striving to
restrict his estimate of the extent of the operation of other agencies,
still I readily admit that valuable truth and good instruction are
to be gathered from his opinions on this branch of his subject.
He has enabled me to see errors in, or exceptions to the extent of
my own first opinion, as heretofore stated. That opinion, which
claimed absolute permanency for all the lime in soil (always ex-
cepting the minute portion taken up by plants), and Prof.
Johnston's opinion of the great waste and speedy removal of all
the lime used as manure, were both carried to very erroneous ex-
tremes. The true doctrine will be found between those extremes ;
which I trust that I have now reached, and will endeavour to
indicate.

As strenuously as formerly, I still assert and maintain the per-
manency of lime in soil, for such amount of quantity as is at the
time acting chemically, or as manure. That quantity is very small,
compared to what is in some highly calcareous soils — ^perhaps not
usually more than 1 per cent, of the whole tilled layer. Yet this
small quantity performs all the useful manuring functions of lime ;
and any excess of this earth, beyond that amount, has no manuring
or beneficial action. It is merely a mechanical earthy ingredient —
which, if large, may do some good, or, as likely, some harm by its
presence and its mechanical bearing on the texture of the soil, but
is not in the least a fertilizing agent. Upon any suoh surplus
quantities of either lime or carbonate of lime in soil (and perhaps
also some other salts of lime not required by and combined with
the soil, and therefore in excess), the solvent power of rain-water
may act, and the lime be gradually thereby removed, according to
the operation of chemical laws, in the manner stated by Prof.
Johnston. But with regard to the small quantity of lime required
as manure, it is (according to my original views before presented,
p. 96) combined chemically with the alimentary organic matter,
and both these, with the soil itself, and this state of combination,
is safe from solution or loss. The quantity of lime which may be
required and used as manure by a soil, varies at diff'erent times
according to the changes of condition. The more putrescent matter
the soil receives, as manure, the more lime will be required to
combine with, preserve, and properly utilize the organic and ali-
mentary matter. Any excess of lime, whether bestowed by nature,

USEFUL APPLICATIONS TO PRACTICE. 211

or as manure by man, beyond the present wants of the soil, is
only of value so far as being there ready for any future increased
demand of the soil, and so may supersede the necessity of another
supply being required as soon. Therefore, however active may be
the solvent power of water, and however rapid the consequent
waste of the excess of lime in the soil, the operation can detract
nothing from any manuring value, or quantity of the lime, pre-
viously and then existing.

The statements and reasoning of Prof Johnston brought to prove
the waste and final disappearance of all lime used as manure, how-
ever inconclusive for his object, furnish important truths for
practical use. We may thence deduce additional reasons for the
impropriety of laying on at once too much marl or lime for the then
wants of the soil ; and also of the usual unequal difi"usion, which
serves to make even a light dressing excessive in many spots, while
entirely wanting in others. Not only, as I had before urged, is all
such excess of quantity, whether general or partial, a waste of
labour, a conversion of active to dead capital, and the causing
danger of actual injury to crops — but further, such excess of lime,
or carbonate of lime, is subject to more or less waste, by solution
and removal, so long as it remains superfluous, and not required
for immediate use by either the soil or growing plants. It is such
excess as this in soils, that furnished all the wasted lime found by
chemists in the waters discharged by drainage from limed lands.
Still more extensive natural operations pf the same kind, and
stronger proofs, are to be seen in all lime-stone and highly cal-
careous regions. The rain-water filtrating through such rocks and
soils, becomes universally and highly charged with lime ; of which
a large portion is removed and lost to the place of its origin, by
flowing oflf into sources of springs and streams. Another portion,
by filtration, may sink deep into the earth. In limestone and chalk
regions, indications of the quantity of lime dissolved by rain-water,
from the rocks and soil, and carried off by springs, may be observed ^
not only in the lime-impregnation of spring-water, but also in the
deposition of travertine, or calcareous tufa, at the rapids of streams ;
and of the loss by filtration in the stalactite deposits in every
cavern of the earth.

There remains to state one other manner of the loss of lime in
soil, which is mentioned by Prof. Johnston, and also other authors,
as being a common, if not a general result in England. This loss
is caused by the tendency of lime, which has been applied, to sink
below the upper soil. " It has long been familiar to practical men,''
says Johnston, ^' that when grass lands, which have been limed on
the sward, are after a time broken up, a white layer or band of
lime is seen at a greater or less depth beneath the surface, but
lodging generally, where it has attained its greatest depth between

212 SINKING OF LIME.

the upper, loose, and fertile, and the lower, more or less impervious
and unproductive soil. In arable lands, the action of the plough
counteracts this tendency in some measure, bringing up the lime
again from beneath, and keeping it mixed with the surface mould.
Yet through ploughed land it sinks at length, especially where the
ploughing is shallow ; and even the industry of the gardener can
Bcarcely prevent it from descending beyond the reach of his spade."
(p. 397.)

Such results, frequent as they doubtless are in England, are cer-
tainly very rare, and of no material disadvantage in this country.
Indeed, until very lately (in 1851), I had never heard of any such
case. But then I learned from Mr. John A. Selden, that he has
observed this effect on his highly improved and well limed farm,
Westover. I had before inferred that this sinking of lime, in its
separate and pure state, could not occur except where it had been
applied in excess — as must be generally done in the usual heavy
applications in England; and that it was only the excess of lime,
which the soil did not then need, and with which, therefore, the
organic matter could not combine, that could thus continue sepa-
rate, and sink through the open soil. If such combination had
taken place (as I suppose of a barely sufficient application), of all
the lime with the organic matter, and of both with the other earthy
parts of the soil, then the lime could not separate from its combi-
nation, and of course could not sink alone. Neither could it carry
with it the other matters in combination. This sinking, it seems,
does not occur with marl, or other " impure calcareous manures,"
but with the finely powdered burnt lime only. When breaking up
land for a second cultivation subsequent to its having been marled,
I have often seen the plough bring up marl, unchanged in appear-
ance, from the bottom of the furrow. But this had been before
turned under (when fii'st spread) to that depth, and had not been
reached and intermixed by the after tillage. Caustic lime is applied
in England very heavily — often as much as 300 bushels, or more,
unslaked, to the acre — and repeated at intervals of about twenty
years. And these, or lighter dressings, must often occur on soils
before calcareous, either naturally, or made so by previous liming.
In either of these cases, I would deem any addition of lime, how-
ever small, to be in excess, for the time ; and of course such ex-
cessive quantity would remain uncombined, and therefore subject
to waste. In this country, all liming has been given in compara-
tively light dressings, and very rarely, if ever, to a calcareous soil ;
and therefore it was rare that any portion of the lime was in
excess, and consequently remained separate and uncombined. And
it is because of these very different conditions that the sinking of
limC; an effect so common and notorious in England, should be so

RECAPITULATION. 213

nncommon, and not to be counted as a loss or disadvantage in
practice, in this country.

The foregoing reasoning, and the conclusions thereby reached, in
regard to the duration of calcareous manures, may be deemed a
continuation of the subject of Chap. VIII., ^^ on the mode of ope-
ration by which calcareous earth increases the fertility and pro-
ductiveness of soils.'' It may be useful here to recapitulate, and
bring together in a small space, the main positions which I have
asserted and maintained.

1. Besides the chemical power and action of calcareous earth as
manure, to neutralize acids, to alter and improve the texture of
soils and their relation to moisture, and also other beneficial
agencies, before discussed at length, the principal and most import-
ant action of the carbonate and other subsequently resulting salts
of lime, in soils, is the combining with organic or alimentary ma-
nures, and also with other earthy parts of the soil. The several
matters, so combined, are rendered, by their combination, fixed in
the whole soil, and secure from waste — and from other diminu-
tion, except for the supply of alimentary matter to growing plants.
To this extent, then, and with the exceptions stated, the combined
matters would be permanent. For this purpose, and to the extent
required by growing plants, their vital forces can decompose the
combination of organic, calcareous, and other earthy constituents,
and take from it freely the parts which the plants require from the
soil for their support. The organic part of the compound is mainly
drawn upon, and diminished by growing plants ; the calcareous (or
other lime) part thus furnishes an extremely small amount only.
Putrescent matter, if again supplied to the soil, will replace in the
combination whatever organic matter had been withdrawn by grow-
ing plants. It the soil is not allowed to obtain the requisite sup-
ply of organic or putrescent matter, the fertility of the soil will
continue to be reduced by growing crops gradually exhausting the
previous supply ; although the lime parts of the soil may not be
appreciably lessened. If, on the contrary, putrescent matter shall
be furnished to a calxed soil, or be permitted to accumulate in it
by natural means, in greater quantity than the lime parts cau
combine with, more lime will be required.

2. If without such state of combination existing, owing to the
absence or insufiicient quantity of either part, the excess of the
other part would be subject to, and continually undergoing waste.
If the part in excess was the putrescent, or organic, it would
rapidly and entirely be removed by decomposition, solution, and
other natural modes of its waste. If the excessive matter was in
lime, whether caustic, or carbonated, or as any other soluble salts
of lime, this also would be gradually dissolved, and lost; and
though the progress of such waste would be very slow^ yet in the

214 DURATION OP ORGANIC MANURES.

course of long time it miglit be very considerable; or possibly (as
asserted by other autliority) nearly comprete.

3. According, then/ to the condition of excess of either of the
parts necessary for the fertilizing combination above stated, either
the organic matter or the lime in soil might be wasting, and the
other part for the time remain fixed, and safe from diminution —
always excepting the portion, large or small, taken up by and re-
moved in the crops.

If I have succeeded in establishing the foregoing views of the
permanent operation of calcareous manures, it will involve the
strong probability, if not certainty, of another result, to which
assent would be still more difficult to obtain, without good reasons
being shown.

Though probably all observing and practical farmers would be
ready to admit the proposition, that the natural and peculiar quali-
ties of good soils, including their measure of productive power, are
permanent, (which is but stating, in other words, that the good effects
of calcareous manures are permanent), still perhaps few would
grant the possibility of permanency of effect to putrescent manures
also, when added thereafter. Yet this latter proposition is as legi-
timate a deduction from the former, as the former proposition is
from the theory which has been maintained of the action of calca-
reous manures. The attention of the reader is requested to the
argument which will now be offered to sustain this important de-
duction.

We have all been trained to consider farm-yard and stable-ma-
nures, dung, and all vegetable and other putrescent matters, when
applied to soils, as having temporary effects only ; and whether the
effects lasted for but the first crop, as on acid sandy soils, or for
four, six, or even eight years on well constituted natural soils, still
the effects were truly, as usually considered, only for a limited
time, and would at some period be totally lost ; and the ground so
manured would return to the same state of less productiveness, as
of the surrounding land, previously equal, and which had received
no such manuring. Such views are almost universal ; and the ut-
most that would be claimed by the most zealous and sanguine ad-
vocate for extending the effect of such manures, would be a protracted
though still limited and temporary duration of action. And the
actual results would always accord with these opinions, (and also
with my theory of the action of calcareous manures), both on good
and on bad soils, before making them more calcareous. All natural
soils (not excessively and injuriously calcareous) have secured by
their natural powers and facilities, and have had fixed in them, as
much alimentary or organic matter as their natural ingredient of
lime could combine with. If that ingredient had been very small,
the soil would be poor ) if- large^ and not so large as to be hurtful,

DURATION OF ORGANIC MANURES. 215

then the soil would be rich. But in neither case would there be
power in the soil to combine with an additional supply of aliment-
ary manure ; and if such were applied, it would be exhausted and
pass away, rapidly on the bad soil, and more slowly on the good j
but certainly, in the end, on both.

Again, suppose the soils to be more or less exhausted by scourg-
ing cultivation. Then their actual amount of alimentary matter
would have been reduced below what their respective shares of
lime could combine with and retain, under a state of nature, or of
mild tillage. Then, if alimentary manures were applied, so much
as was required for combination by the lime present would be as
permanently fixed as if the original fertility had never been ab-
stracted ; and any additional quantity and excess of manure, not
being so combined and fixed, would be totally lost in more or less
time, as in the previously supposed case.

Lest these propositions may not appear, because of their novelty,
perfectly clear and unquestionable to every reader, an illustration
will be oiFered which can scarcely fail to induce their general and
ready admission. Suppose a cultivator to have two fields, one of
bad and poor soil naturally, and the other of the best natural qua-
lity— and both having been brought under cultivation together,
and kept under the same rotation of crops and other management.
Suppose further that the equal and uniform course of cropping
has been such (whether taking one or two or three grain crops to
one year-of rest, and resuscitation), that both fields have neither
been reduced nor increased in average product, since brought under
regular tillage ; and that such average product, when of corn, is
equal to 10 bushels per acre on the poor, and 50 bushels on the
rich soil. Now, these different products are derived from the dif-
ferent funds of alimentary and putrescent manure originally sup-
plied to the soil by nature, (whic|?L were just so much as the lime
of each soil could combine with) ; and, under the supposed degrees
of exaction and relief, counteracting each other under tillage, the
same rates of product may be obtained for ever. And the yielding
of 50 bushels by the one soil operates no more to reduce its after-
power of production, then the yield of the other of but one-fifth of
that amount of crop. The yield from each soil, at and for the time,
is certainly so much reduction of its productive power ; but the re-
cuperative power of each (to seize upon and retain new supplies for
fertilization, drawn from the atmosphere, and from the grass and
weeds grown and suffered to decay on the land,) is in proportion
to the yield ; and the vegetable growth serving for manure, and
atmospherical influences, during a year of rest, will continually
give to the good soil the renewed power of producing again its large
crop, as certainly as to the poor soil the power of still continuing
to produce its small crop. It is not that the natural alimentary

216 DURATION or ORGANIC MANURES.

manure in the soil is not taken away in part, by the growth and
removal of every crop, but that such waste is continually compen-
sated by new acquisitions. And whether such new supplies of
alimentary matter be furnished in part during every day, or in
every year, or only during the one term of rest in the whole course
of crops, the practical result is the same, of the natural or original
amount of alimentary manure remaining finally undiminished.

So far as to the absolute permanency of putrescent or alimentary
manures supplied by nature. Next let us see whether the same
reasoning, and also experience, so far as yet obtained, do not in
like manner prove the permanency of putrescent manures applied
after calcareous manures. The poor soil just adduced for illustra-
tion, while having its natural alimentary ingredient and its natural
supply of lime thus balanced and proportioned to each other, was
supposed to produce at the rate of 10 bushels of corn to the acre,
and to remain at or near that rate of productive power. Suppose
then marl to be applied in such quantity as would give enough cal-
careous earth to combine with twice as much new alimentary mat-
ter as the soil before held. Suppose further, that the soil so marled
is not left to draw and store up this now needed stock of alimentary
manure by its newly increased poweii, (and as would be done in
sufficient time, if under favourable circumstances of tillage), but
that so much putrescent manure is applied to the soil, gradually
and judiciously, as can be combined with and held by the supply
of calcareous earth ; and that such addition of manure gives to the
soil a power to produce 30 bushels of corn. As soon as this com-
bination is completely made, the soil is in precisely the same con-
dition as to its newly increased rate of product of 30 bushels, as
before to that of 10 bushels ; and the new and larger supply of
putrescent manure must be as permanent as was the natural and
smaller supply.

But it is not contended that the mere application of vegetable
or other putrescent manure, under such circumstances, secures the
permanency of effect of all thus applied, but only of so much as
can be and is combined with the calcareous earth. And many cir-
cumstances may and do usually obstruct the immediate and com-
plete combination from taking place. To insure the perfect and
full result, the intermixture of the calcareous and the putrescent
matters, and in due proportions, must be perfect, and no excess of
the latter must remain anywhere in the soil ; the putrescent mat-
ter must also be in the particular state of decomposition (whatever
that may be) to enter into combination ; and moreover there must
be enough and equally diffused moisture, without which no chemi-
cal combination can take place. Now, as some and probably all
these conditions must necessarily be deficient in every case of ap-
plying putrescent matters to marled land, it must follow that. much

OROANIC MANURES MADE PERMANENT. 217

of the manure must remain uncombiued for some length of time ;
and during that time is as liable to be wasted and exhausted as if
in any other soil. And hence, and the more as the dressing is
lavish, farm-yard and stable manure so applied must be expected to
yield more for the first and second year, while the excess is wasting,
than afterwards. But after this first waste and exhaustion has
been suffered, whatever of the manure remains to the soil, say for
the next ensuing rotation at latest, must be fully combined with
and fixed in the soil, and will be permanent for all future time,
under proper, judicious, and also the most profitable course of-
cropping. This first waste probably cannot be entirely prevented;
but it can be much lessened by care. And to this end, putrescent
manure should not be applied heavily at once, but lightly, and re-
peated subsequently, and should be well scattered and equally dif-
fused over the ground. Its subsequent decomposition being slow,
and the products being gradually, as well as surely, presented to
the ' lime diffused previously throughout the soil, will also tend to
remove as much as possible of the manure from the condition of
being fleeting and wasting, to that of being fixed and permanent.

Next let us see how far facts and experience sustain this reason-
ing. It is conceded that the time since marling was commenced in
Virginia, and since correct views of the action of calcareous ma-
nures were entertained and acted on in any case, has been too short
to furnish decisive proofs. But so far as accurate facts can thus
be referred to, they fully sustain the foregoing doctrine, not only
of the permanency of calcareous manures, but also of putrescent
manures in combination therewith. Some of these facts will be
mentioned generally.

However much in accordance with the theory of the action of
calcareous manures, this absolute permanency of effect given
thereby to putrescent manures was not at first counted on or ex-
pected, and was not known until it was forced on my observation
by long-continued results. My own practice is not only the oldest,
but is all that I can refer to for proofs. And until all my marling
was completed, and indeed for some time after, but little care was
used by me to make and apply putrescent manures. This culpa-
ble neglect was the result of the habits caused by the disappoint-
ments and losses experienced in manuring long before. From the
same ignorance and carelessness in this respect, no experiments on
the durability of putrescent manures were made until long after,
and then injudiciously. Thus, in experiments 4, 9, and 11 (pp. 120,
131, 134), the putrescent manure applied was in quantity much too
great for the calcareous earth to combine with at once, even if the
recent and irregular scattering of both kinds of manure had not
prevented their meeting in proper proportions. For like reasons, of
all the putrescent manures applied on the farm, and since larger
19

218 ACTUAL DURATION OP EFrECTS.

quantities have "been used, there is mucli more of early than con-
tinued effect. Still, so far as known and believed, there is always
more or less of abiding effect, and which I infer will be permanent.

But wider scope for observation has been afforded in the increas-
ing productiveness of all the marled lands, kept under what was
deemed not too frequent tillage. Neither has the tillage been al-
ways mild, nor the rotation uniform; and latterly the grain crops
have been made more frequent than before, and much more grazing
permitted.* Still, even where no prepared putrescent manures
have ever been applied, and putrescent matters have been furnished
only from the growth of the land itself during its share of rest in
each course of crops, there has been a regular increase of produc-
tiveness of the grain crops, in every successive rotation. — [1842.3
In one connected clearing, of what I found as poor forest land^
now making 85 acres, the marling was commenced in 1818, and has
been continued, as the successive clearings extended, to 1841,
The earliest effects of the applications were always satisfactory,
but they have regularly and largely increased with time. Thus^
when under the last crop of corn (in 1839), the crop on the last
finished marling, though perhaps thereby nearly doubled in pro-
duct, was obviously and considerably less than that of four to six
years earlier — that again as inferior to that of the marling of ten
to fifteen years — and the crop on the marling of 1821 and earlier,
decidedly the best of all, under circumstances otherwise equal. For
the limited time of twenty-three years, and without any careful and
accurate experiment or observation having been made for this special
object, there could not well be stronger practical proof of the per-
manency of the vegetable manures stored up by the marl.

If we keep in mind the mode by which calcareous manure acts,
its effects may be anticipated for a much longer time than my ex-
perience extends. Let us trace the supposed effects, from the
causes, on an acid soil kept under meliorating culture. As soon
as applied, the calcareous earth combines with all the acid then
present, and to that extent is changed to the hum ate and other
vegetahle salts of lime. The remaining calcareous earth continues
to take up the after formations of acid, and (together with the
salts so produced) to fix putrescent manures, as fast as these sub-
stances are presented, until all the lime has been combined with
acid, and all their product is combined with putrescent matter.
Both those actions then cease. During all the time necessary for
those changes, the soil has been regularly increasing in productive-
ness ; and it may be supposed that, before their completion, the

* The land, however much improved in richness hy being secured from
grazing so long, had in consequence become too "puflfy" for wheat, and
also full of insects and bad weeds ; for all which grazing at some proper
timo of the rotation ia beneficial, and indeed essential.

SUPPOSED PROGRESS OP ACTION. 21^

product had risen from ten to thirty bushels of corn to the acre.
The soil has then become neutral. It can never lose its ability
(under the mild rotation supposed) of producing thirty bushels ;
but it has no power to rise above that product. Vegetable food
for plants continues to form, but is mostly wasted, because the
salts of lime are already combined with as much as they can act
on ; and whatever excess of vegetable matter remains in the soil,
is kept useless by acid also newly formed, and left free and noxious
as before the application of calcareous earth. But though this
excess of acid may balance and keep useless the excess of vegeta-
ble matter, it cannot affect the previously fixed fertility, nor lessen
the power of the soil to yield its then maximum product of thirty
bushels. In this state of things, sorrel may again begin to grow,
and its return may be taken as notice that a new marling is needed,
and will afford additional profit, in the same manner as before, by
destroying the last formed acid, and fixing the last supply of vege-
table matter. Thus perhaps five or ten bushels more may be
added to the previous product, and a power given to the soil gra-
dually to increase as much more, before it will stop again for
similar reasons, at a second maximum product of forty or fifty
bushels. I pretend not to fix the time necessary for the completion
of one or more of these gradual changes ; but as the termination
of each, and the consequent additional marling, will add new pro-
fits, they ought to be desired by the farmer, instead of his wishing
that his first labour of marling each acre may also be the last re-
quired. Every permanent addition of five bushels of corn, to the
previous average crop, will more than repay the heaviest expenses
that have yet been encountered in marling. But whether a second
application of marl is made or not, I cannot imagine such a con-
sequence, under judicious tillage, as the actual decrease of the
product once obtained. My earliest marled land has been severely
cropped, compared to the rotation supposed above, and yet has
continued to improve, though at a slow rate. The part first marled,
in 1818, had only four years of rest in the next fifteen ; and
yielded nine crops of grain, one of cotton, and one year clover
twice mowed. This piece, however, besides being sown with
gypsum (with little benefit), once received a light cover of rotted
corn-stalk manure. The balance of the same piece of land (Exp.
1) was marled for the crop of 1821 — has borne the same treat-
ment since, and has had no other manure, except gypsum once
(given in the natural gypseous earth found on the farm),* in 1830,
which acted well. These periods of twelve and fifteen years (even
though now extended to and confirmed by nine years more of ex-
perience) are very short to serve as grounds to decide ( n the

^' See accounts of tliis bed of " gypseous earth" in vol. 1 of Farmers'
Register, and of its effects, in success and failure, in vol. 10.

220 THE EXHAUSTION OF CALXED LAND.

eternal duration of a manure. But it can scarcely be believed
that the effect of any temporary manure, would not have been
somewhat abated by such a course of severe tillage. Under milder
treatment, there can be no doubt that there would have been much
greater improvement. — [1842.]

If subjected to a long course of the most severe cultivation, a
soil could not by such course alone be deprived of its calcareous
ingredient, whether natural or artificial : but though still calcare-
ous, it would be, in the end, reduced to barrenness, by the exhaus-
tion of its vegetable matter. Under the usual system of exhaust-
ing cultivation, marl certainly improves the product of acid soils,
and may continue to add to the previous amount of crop, for a
considerable time ; yet the theory of its action instructs us, that
the ultimate result of marling, under such circumstances, must be
the more complete destruction of the land, by enabling it to yield
all its vegetable food to growing plants, which would have been
prevented by the continuance of its former acid state. An acid
soil yielding only five bushels of corn may contain enough food for
plants to bring fifteen bushels ; and its production will be raised
to that mark, as soon as marling sets free its dormant powers. But
a calcareous soil reduced to a product of five bushels, can furnish
food for no more ; and nothing but an expensive application of
putrescent manures can render it worth the labour of cultivation.
Thus it is, that soils, the improvement of which is the most hope-
less without calcareous manures, will be the most certainly im-
proved with profit by their use.

CHAPTER XXIII.

GENERAL OBSERVATIONS ON THE VALUATIONS OP LANDS AND
THEIR IMPROVEMENTS, AND THE EXPENSES AND PROFITS OF
MARLING.

Proposition 5 — concluded.

At this time there are but few persons among us who doubt the
great benefit to be derived from the use of marl; and many of
those who formerly deemed the early practice the result of folly,
and a fit subject for ridicule, now give that manure credit for vir-
tues which it certainly does not possess ; and, from their manner
of applying it, seem to believe it a universal 'cure for sterility.
Such erroneous views have been a principal cause of the many
injudicious and even injurious applications of marl. It is as

ESTIMATING VALUES OF LAND. 221

necessary to moderate the ill-founded expectations whicli many
entertain, as to excite the too feeble hopes of others.*

The great improvement of land and its products, to be caused by
marling, and its long duration, if not absolute permanency, have
been established, I trust, beyond question, by the foregoing argu-
ment and proofs. Still, any degree of improvement may be paid
for too dearly ; and the propriety of the practice must depend on
the amount of its clear profits, ascertained by fair estimates of the
expenses incurred.

With those who attempt any calculations of this kind, it is very
common to set out on the mistaken ground that the expense of
marling should bear some proportion to the selling price of the
land; and without in the least underrating the effects of marl,
they conclude that the improvement cannot justify an expense of
six dollars on an acre of land that would not previously sell for
four dollars. Such a conclusion would be correct if the land were
held as an article for sale, and intended to be disposed of as soon
as possible ; as the expense in that case might not be returned in
immediate profit, and certainly would not be added to the price of
the land by the purchaser, under present circumstances. But if
the land is held as a possession of any permanency, its previous
price, or its subsequent valuation, has no bearing whatever on the
amount which it may be profitable to expend for its improvement.
Land that sells at four dollars, is often too dear at as many cents,
because its product will not pay the expense of cultivation. But
if by laying out for the improvement ten dollars, or even one
hundred dollars to the acre, the average increased annual profit
would certainly and permanently be worth ten per cent, on that
cost of improvement, then the expenditure would be highly expe-
dient and profitable. We are so generally influenced by a rage for
extending our domain, that another farm is often bought, stocked,
and cultivated, when a liberal estimate of its expected products,
would not show an annual clear profit of three per cent. : and any
one would mortgage his estate to buy another thousand acres, that
was supposed fully capable of yielding ten per cent, on its price.
Yet the advantage would be precisely the same, if the principal
money was used to enrich the land already in possession (without
regard to its extent, or previous value), with equal assurance of its
yielding the same amount of profit.

Nothing is more general, or has had a worse influence on the
state of agriculture, than the desire to extend our cultivation and
landed possessions. One of the consequences of this disposition
has been to give an artificial value to the poorest land, considered

* This introductory p.aragrapli was prepared for and first appeared in tJiO
edition of 1832, to which time it was especially applicable.
19 ''^

222 ■ TRUE MODE OF ESTIMATION.

merely as so much territory, while various causes have concurred
to depress the price of all good soils much below their real worth.
Whatever a farm will sell for, fixes its market value 3 but by no
means is it a fair measure of its value as permanent farming
capital.

The true value of land, and also of any permanent improve-
ments to land, I would estimate in the following manner : Ascer-
tain as nearly as possible the average clear and permanent annual
income, and the land is worth as much money as would securely
yield that amount of income, in the form of interest — which may
be considered as worth six per cent. For example, if a field brings
ten dollars average value of crops to the acre, in the course of a
four-shift rotation, and the average expense of every kind neces-
sary to carry on the cultivation is also ten dollars, then the land
yields no clear profit, and is worth nothing. If the average clear
profit was but two dollars and forty cents in the term, or only sixty
cents a year, it would raise the value of the land to ten dollars ;
and if six dollars could be made annually, clear of all expense, it
is equally certain that one hundred dollars would be the fair value
of the acre. Yet if lands of precisely these rates of profit were
offered for sale at this time, the poorest would probably sell for
four dollars, and the richest for less than twenty dollars. In like
manner, if any field, that paid the expense of cultivation before,
has its average annual net product increased six dollars for each
acre, by some permanent improvement, the value thereby added to
the field is one hundred dollars the acre, without regard to its for-
mer worth. Let the cost and value of marling be compared by
this rule, and it will be found that the capital laid out in that mode
of improvement will seldom return an annual interest of less than
twenty per cent. — that it will more often reach to forty — and in
very many cases will exceed one hundred per cent, of annual and
permanent interest on the investment, or total cost of the marling.
The application of this rule for^ the valuation of such improve-
ments will raise them to so large an amount, that the magnitude
of the sum may be deemed a sufficient contradiction of my esti-
mates. But before this mode of estimating values is rejected,
merely for the supposed absurdity of an acid soil being considered
as raised from one dollar, or nothing, to thirty dollars, or more,
per acre, by a single marling, let it at least be examined, and if
erroneous, its fallacy exposed.

If the reader will accompany me through some detailed estimates
of values, and arithmetical calculations, in regard to the grounds
of which we cannot differ, the truth of the results which I claim
will be made manifest, however startling and monstrous they may
appear to some persons at first glance.

Assuming as sound and unquestionable the grounds for cstimat-

TRUE MODE OP, ESTIMATION. 223

ing the intrinsic value of lands, as stated generally above, let us
illustrate the position more particularly. The principle of valua-
tion is that the land is worth to its proprietor and cultivator such
sum of money as would yield in annual interest the same amount
as the net annual product of the land, after paying for all labour,
attention, expenses, and risks. Further, to simplify the calculation,
and also to suit the course of culture to the more general practice
of the country, let us suppose the land in question to be cultivated
under the ordinary three-shift rotation, of 1st, corn, 2d, wheat (or
oats), 3d, at rest, with no grazing when the land is poor, and with
but partial and moderate grazing (or mowing of clover) when im-
proved or rich.

Then suppose a field of the poor and thin soil most common ia
lower Virginia, under this treatment for some years previously, to
produce, on the general average, 10 bushels of corn to the acre,
and five bushels of wheat, or its equivalent value of oats ; and the
value of the corn, at the barn, to be 50 cents the bushel, and of
the wheat $1. And let the joint and total expenses of preparation,
tillage, seed, harvesting, thrashing, &c., for market (or for home
use), and of superintendence and care of both the corn and wheat
or oat crops, be counted as being over and above the value of the
offal (stalks, straw, &c.) of the crops, by ^10 for the two years.
Then the full statement will be as follows :

First year, product in corn per acre, 10 bushels, at 50 cents . $5
Second year, wheat, 5 bushels, at $1 . . . . .5
Third year, no crop or money product, and no expense . . 0

Total product of the three years' rotation .... $10
Cost of cultivation, &c., of the crops 10

Net profit 00

However wretched may be the foregoing exhibition of products,
it will be admitted to be abundantly liberal' by all persons ac-
quainted with lower and middle Virginia, for a very large propor-
tion of the cultivated lands. Yet such lands might sell at prices
varying from $3 to $6 the acre ; and that without a view to their
being improved, and even before calcareous manures were thought
of as means for improvement. Yet the conclusion is evident, that
such land, no matter what may be its then selling price, (or specu-
lative appreciation sometimes caused by the efibcts of paper-money
and fraudulent bank issues), is worth not one cent for cultivation,
or for the benefit of the proprietor and cultivator.

Next, suppose the land in question to be properly marled, and
at the unusually heavy expense of $7 the acre. This rate is more
than double the usual expense for a full and sufficient dressing,
when the marl is obtained on the farm where applied. Suppose

224 ESTIMATED VALUES FROM CALXINQ.

•

also that tlie increase of products, as shown in the second course
of the rotation (beginning three years after the application), is
equal to 100 per cent, on the production previous to marling. This
estimate is quite low enough, as all experience has shown. Upon
such land, and so treated, this degree of increase may very often,
be obtained upon the first crop of the first course ; and, even if no
auxiliary means of enriching be afterwards used, the rate of in-
crease will be more and more for each of sundry succeeding courses
of crops thereafter. Then let us test the value of the returns by
figures as before :
First year, product in corn per acre, 20 bushels, at 50 cents . $10

Second year, wheat, 10 bushels, at $1 10

Third year, clover, most of it left as manure to the land, and
no present pecuniary profit counted here . . . .00

20
Total expenses of cultivation, &c., as before, in two years . 10

Net product, or clear profit of cultivation in the term of three
years $10

This is all so much increase of net annual product upon the pre-
vious rate; and the amount, $3.33 yearly, is the interest (at 6 per
cent.) of something more than a capital of $55. And therefore,
according to these grounds of estimate, $55 per acre is the increase
of intrinsic value given to the land by marling alone, or $48 the
clear gain made by the operation, after deducting $7 paid for the
marling of the land ; and this without regard to what might have
been its previous intrinsic value, or its former or its more recent
market price. The more rigidly this mode of estimate is scruti-
nized, the more manifestly true will be found the results. The
premises assumed, in the supposed efiects and profits of marling,
will not be objected to (unless as being too low) by any person
who is well informed by practice and experience.

But there is one important apparent omission of a proper charge-
in the last statement of expenses. This is the increase of labour
of tillage, harvesting, &c., caused by the crop being doubled in
quantity. This is certainly a fair ground of charge ) and, if esti-
mated alone, would serve to reduce considerably the statement of
increased net product, and consequently of increased value of land.
But there were also omitted sundry items of increased production,
which together would undoubtedly much more than compensate for
the increase of labour in tilling a deeper and richer soil, and in
barvesting, removing, and preparing for sale or use, a double quan-
tity of crops. These items of gain are, first, the additional ofial,
in corn-stalks, fodder, and shucks, and wheat or oat straw and
chafi"; second, the limited proportion of clover grazed or mowed ;

ESTIMATED VALUES OP LANDS. 225

and third, the further gradual increase of crops, in subsequent
time. Probably the first class of items alone would balance the
increased expense of labour; if not, the addition of the second
(the clover) certainly would be enough. And if that be doubted,
the subsequent annual increase upon the first doubling of the crops
(which only is estimated above) will not only furnish a fund to
meet any such deficiency, but also will greatly, and beyond any
calculation here attempted, augment the whole profit of marling,
and consequently the intrinsic value of the land to the proprietor.

I admit the practical difficulty of applying this rule for estimat-
ing the value of land, or of its improvement, however certain may
be its theoretical truth. It is not possible to fix on the precise
clear annual profit of any farm to its owner and cultivator ; and
any error made in these premises is increased sixteen and two-third
times in the estimate of value founded on them. Still we may ap-
proximate the truth most nearly by using this guide. The early
increase of crops from marling will, in most cases, be a full equal
increase of clear profit, (for the subsequent improvement and the
additional ofi"al will surely pay for the increase of labour) ; and it
is not very difficult to fix a value for that actual increase of crop,
and thereby to estimate the value of the improvement, as newly
created farming capital.*

This mode of valuing land, under a different form, is univer-
sally received as correct in England. Cultivation there is carried
on almost entirely by tenants ; and the annual, rent which any
farm brings, on a long lease, fixes beyond question what is its an-
nual clear profit to the owner. The price, or value of land, is
generally estimated at so many " years' purchase," which means as
many years' rent as will return the purchaser's money. There, the
interest of money being lower, increases the value of land accord-
ing to this mode of estimation ; and it is generally sold as high as
twenty years' purchase. My estimate is less favourable for raising
the value of our lands, as it fixes them at sixteen and two-thirds
years' purchase, according to our higher rate of interest on money.

But though this rule for estimating the true value of land, and
of the improvements made by marling, may be unquestionable in
theory, still a practical objection will be presented by the well
known fiict that the income and profits of farmers are not usually
increased in proportion to such supposed values of improvements,
nor is there found such a vast disproportion, as this rule of estimat-
ing values would show, between the profits of the tillers of poor
and of rich lands. These positions are admitted to be generally

* No degree of uncertainty in the application, however, detracts from the
truth of this rule. For if the annual average net profit derived from marl-
ing be considered as an unknown quantUi/, (x), it is not therefore the less
certain that x X 16f = the Increased intrinsic value of the land.

.226 VALUES OP IMPROVED LANDS.

well founded — "but it is denied that they invalidate the previous
estimates. A farmer may, and generally does, obtain less gross
product from a large or a rich farm, than his more necessitous, and
therefore more attentive and economical neighbour gets from a
smaller or poorer farm, in proportion to the producing power of
each ; and even the same persons, when young and needy, havoi
often made more profit according to their means, than afterwards
when relieved from want, and having lands increased to a double
power of production. These, and similar facts, however general,
are only examples of the obvious truth, that the profits of land
depend principally on the industry, economy, and good manage-
ment of the cultivator ; and that many a farmer, who can manage
well a small or poor farm, is more deficient in industry, economy,
or the increased degree of knowledge required, when possessed of
much more abundant resources. In short, if these considerations
were to direct or influence our estimates, we should not be compar-
ing and estimating the value of lands, but the value of the care
and industry bestowed on their management by their proprietors.

Another objector may ask, ''If any poor land is raised in
intrinsic value (according to this estimate) from one dollar to
thirty, by marling, would a purchaser make a judicious investment
of his capital, by buying this improved land at thirty dollars V' I
would answer in the affirmative, if the view was confined to this
particular means of investing farming capital. The purchaser
would get a clear interest of six per cent., which has always been
deemed a good return from land, and is twice as much as all lower
Virginia now yields, on a general average of the unimproved lauds.
But if such a purchase is compared with other means of acquiring
land so improved, it would be extremely injudicious; because
thirty dollars expended in purchasing and marling suitable land,
would serve both to acquire and improve, to as high a value, five
or six acres.

The immense quantity of rich and low-priced land held for sale
"by our government, and always in market, and the flood of emi-
gration thereby drawn from the old states, and especially from
Virginia, have served more than all other causes to depress the
selling prices of our lands, and to discourage their being improved.
So long as rich land can be bought in any quantity for SI. 2 5 the
acre, though it may be under forest growth, and on the frontier of
civilization, there will be thousands of improvident or adventurous
landholders in the old states always striving to sell their impover-
ished farms, and to buy new settlements in the west — rather than
resort to what they deem the slow and costly means for restoring
or increasing fertility. And though very many others now believe
that it is far more profitable to improve their own poor land than
to emigrate to new and rich — and act upon that belief in buying

CAUSE OP LOW PRICES OP LANDS. 227

to improve, as well as improving the land held previously — still
their very limited numbers and action can go but little way to
lessen the excess of supply of land offered for sale, over the exist-
ing demand of purchasers. We all know that a great excess of
supply over demand of any commodity, no matter how essential
for the use or even existence of the consumers, is enough to reduce
the market price to almost any extent. Even in regard to corn,
which every man requires for sustaining life, and which will be
wanting by every one, in certain and known quantity, for the next
as well as the present year, still a great excess of supply may re-
duce the price of this most indispensable commodity to one-third,
or even one-tenth, of what it may command when the demand as
greatly exceeds the supply. The market price of Indian corn in
Virginia, where it is the principal grain consumed by both man
and beast, has frequently, within a few years' time, ranged from
40 to 100 cents the bushel, according to the preponderance of
supply and demand. Indeed, within my farming life, it has sold
as low as 20 cents; and at another time, at $2 the bushel. No
matter what may be deemed the intrinsic value of any commodity,
no buyer will pay for it even half that rate, so long as eager or
necessitous sellers offer the like to him for a foui'th, or for less.
So it is with our land. Such considerations, and the existing state
of our land market, may (and ought to) operate to prevent a buyer
from paying as much as $10 for the land which under different
circumstances of market price he would gladly buy at $50. Yet
in both cases of prices so different, the intrinsic value of the land^
and also its net product, might 'be the same.

The excess of supply over demand not only serves to depress the
selling prices of both good and improvable lands greatly below
their true and productive value, but also it acts with much force to
repress the desire for and prevent the results of improving the
land in possession. For whatever may be the productive value of
any improvements of land, they must be estimated and depreciated
in market price by the same law of supply and demand as deter-
mines the selling prices of other lands of like value. Many par-
ticular farms in lower Virginia, by marling, have been doubled in
gross product, and thereby, perhaps, increased ten-fold in net pro-
duct and in true intrinsic value. And yet, when the death of the
proprietor, and the consequent division of his estate, or other causes,
have compelled the sale of such a farm, the additional price ob-
tained over the market estimation before marling, perhaps has not
paid even the small cost of that improvement. Hence arises a
great discouragement, at this time, to all improvement of land in
Virginia, which acts not only on those proprietors who look forward
to a future sale of their farms, but also on most other persons who
have no such expectations.

^8 INJUDICIOUS MARLING LABOURS.

But the principal discouragement to the proper extension of
marling proceeds from the erroneous and exaggerated estimates of
the difficulty and cost. Estimates of the expenses required for
marling are commonly erected on as improper grounds, as those of
its profits. We never calculate the cost of any old practice. We
are content to clear wood-land that afterwards will not pay for the
expense of tillage ; to keep under the plough, land reduced to five
bushels of corn to the acre; to build and continue to repair miles
of useless and perishable fences ; to make farm-yard manure
(though not much of this fault), and apply it to acid soils ; with-
out once calculating whether we lose or gain by any of these opera-
tions. But let any new practice be proposed, and then every one
begins to count its cost ; and on such erroneous premises, that if
applied to every kind of farm labour, the estimate would prove
that the most fertile land known could scarcely defray the expenses
of its cultivation.

The usual injudicious modes of conducting marling operations
have served greatly to increase the actual cost. Some farmers,
even after some years of such work and experience, still waste
nearly or quite half their labour so employed. Many new begin-
ners, by their greater mismanagement and consequent loss, are so
discouraged as to be stopped almost at the very outset. Thus, a
little, but insufficient amount of experience in marling, is likely to
magnify the supposed difficulties. By such deficiency of judgment
and economy in directing and executing the labours, marling is
often made very costly. But so it would be, without information
or experience, with any other new farming operation. It is as easy
in this as in any other business to work judiciously and economi-
cally J and if so conducted, marling (or liming), where properly
available, will be found the cheapest as well as the most productive
means for fertilization.

The expenses of particular operations of marling, or liming,
have been, and of others may be, easily and correctly ascertained.
So have been, and may be, the early products and pro-
bable abiding profits of particular applications. But these two
actual results cannot be fairly combined, so as to indicate in
general the balance of profit exceeding the expense. For the
measure of increased product is in proportion to the quantity of
marl applied, and the previous want of the land for the application ;
and not to the expense of that application. It may happen that
the most expensive marling may be on land so little requiring that
improvement, or so little fitted to receive such improvement, that
but small benefit is produced. In other cases, where the expense
of marling is the least, because of great facilities, the benefit to the
land may be the greatest. In the former case, of maximum labour
and minimum increase of production, the net profit of the marling

COSTS OP ACTUAL MARLINGS. 229

miglit not exceed 10 per cent, per annum, on the cost — (though I
have never known so little, from any proper application). In the
latter case, of minimum expense and maximum effect of marling,
the net profit might be 200 per cent, per annum on the cost. Most
operations would be much within these extreme results. In much
the greater number of cases of my own labours, and of all others
which ■ have come under my personal observation, and were con-
ducted and applied with ordinary judgment, the net profits have
not fallen short of 50 per cent, per annum on the expense, for the
whole time which has elapsed since the application. How long
such operation may continue, and whether increasing or decreasing,
I leave to be inferred from the preceding facts and reasoning, in
regard to the duration of the effects of calcareous manures. The
grounds of this belief have been already in part submitted, in
sundry statements of particular products, the results of particular
applications. The expenses of particular and large marling opera-
tions have been as carefully noted, and will hereafter be reported
in detail. But for the better understanding of these details, and
more methodical arrangement, they must be postponed until other
explanatory matters shall have been presented. I will therefore
here merely state the general results. In four extensive marling
operations, on three different farms, under different circumstances,
and nearly all of which were unusually difficult and laborious, the
total expenses were severally 142, 971, 86, and 94 cents for the
100 hjeaped bushels of marl, spread upon the fields.

Most of marling labours, under ordinary circumstances of facility
and difficulty, ought not to exceed in cost ^1 for the 100 bushels
of marl applied ; while the ordinary profits thereon will well repay
an expenditure of $6, under existing circumstances ; or of twice or
thrice as much, if lands and their permanent improvements in
Virginia were priced according to their producing and intrinsic
value, and not according to the excess of supply over demand in
the land market.

The argument in support of the several propositions which were
advanced, and have been discussed through so many chapters, is
now concluded. However unskilfully, I flatter myself that it has
been effectually urged; and that the general deficiency in our soils
of calcareous earth, the necessity of supplying it, the profit by that
means to be derived, and the high importance of all these consider-
ations, have been established too firmly to be shaken by either
arguments or facts.

There remain, however, and will be presented in order, other
important matters ; which though not necessary for the mainten-
ance of the series of propositions which have been argued, and
which were too long to have been properly included in that discus-
sion, are not the less deserving of consideration.
20

CHAPTER XXiy.

OTHER FERTILIZING POWERS AND EFFECTS OF CALCAREOUS EARTH.

When stating tlie supposed powers, or modes of operation, of
calcareous earth, or of the salts of lime generally, as ingredients
of soils, by which their presence caused fertility, and their absence
or great deficiency maintained barrenness (Chap. VIII.), no power
or quality was named which had not been either inferred in ad-
vance of any known results of calxing, or observed in natural
soils, or otherwise, soon after the commencement of my practical
applications. Also, subsequently, in Chap. XIX., when either re-
capitulating, or stating for the first time, the results of calxing,
none were named (unless incidentally and slightly), which had not
been obtained from my own practice, or by personal observation of
the practice of intelligent and trustworthy co-labourers in this
mode of improvement. There remain to be presented other or
greater effects than had been anticipated, or known early from ex-
perience ; and also other auxiliary and important causes for such
unexpected measure of benefit produced by calcareous manures.

My own early practice in calxing was mostly on acid soils. The
much smaller surface of neutral soils, though also marled, was not
observed for the effects through a course of years — nor carefully, by
experiment, for less time, in but few cases. On such soils, my
theory promised no early perceptible benefits ; and late returns
could not well be known and estimated, except from large surfaces,
as a whole field, or the greater part of a farm.

But though my high and hilly farm of Coggins had but a small
proportion of neutral soil, most of the lower and level lands on the
tide-water of James river consisted principally of soil of that kind.
These best lands of the lower James (as of all the other tide-waters
of Virginia) have evidently been formed by the deposit of alluvial
earth, subsequent to the general " upheaving" of the higher-lying
and greater body of the surrounding lands from below the bottom
of the ancient ocean ; yet long before the present degree of eleva-
tion of the general surface had been completed, by the producing
geological causes. These ancient alluvial lands are always low, in
comparison to the adjacent lands of different and earlier formation;
yet so much elevated above the present greatest height of the
river, that they have as little of the characteristic defects of ^^low-
ground," as if not of alluvial formation. The common geological
origin of these lands, and their common sources of materials, have
served to eive to them a general uniformity of character and

(230)

. SOILS OP ANCIENT ALLUVIUM. 231

qualities, though with considerable variations of texture and
fertility. Such were the natural soils, generally, of the farms of
Sandy Point, Brandon, Wyanoke, Westover, Eppes' Island, Jor-
dan's Point, Shirley, Curie's Neck, and smaller parts of many
other lands along James river. Some small portions, as on
Wyanoke, w6re so sandy as to suffer loss of soil from high winds,
before being improved by lime, which stopped the further progress
of that injury. Other parts are made objectionably stiff and in-
tractible, by containing too much clay. More generally, the
texture is of, or approaches to medium, or is between the extremes
of sandy loam and clayey loam. The surface is nearly level, but
generally is very slightly undulating, and exhibiting, in the direc-
tion of the depressions and elevations, the course and degree of
violence of the ancient flood of turbid water, which deposited the
soil, and also thus furrowed the surface. All such lands were
originally rich, and of course neutral; but nearly all had been
much reduced in fertility by the exhausting and bad cultivation
formerly general in lower Virginia. A large proportion of these
lands were of that peculiar and best kind of soil known as ^^ mu-
latto,'' or chocolate-coloured. They are reddish brown, showing by
this colour a considerable ingredient of red oxide of iron ; while the
darker tint, friable texture, and growth of these soils, would seem
to indicate a calcareous character and constitution formerly, though
none have been known to be more than neutral, before the artificial
calxing. Before this improvement on all the best of such soils,
clover would grow, and gypsum acted on clover. These ^^ mulatto"
soils have before been incidentally mentioned in this essay ; and
more particular descriptions of several of the best tracts, and of
their recent improvement by calxing, were published in different
parts of the Farmers' Register.*

Reasoning from the modes of operation ascribed to calcareous
earth in Chap. VIII., and in advance of all experience of the effects
of calcareous manures on these fine neutral soils, I had not sup-
posed them capable of deriving much benefit from that mode of
improvement. But very different have been the results. The
effects of calxing thereon, whether by marling or liming, are (as
was expected), scarcely, if at all, perceptible on the first crop j
and even the earliest appreciable benefit is as nothing compared to
the speedy and wonderful effects on acid soils. Still, the improve-
ment is not long in becoming manifest; and within the first round
of the rotation of crops, and especially when clover becomes the
growth of the field, the benefit from the previous calxing is great,
and in the succeeding grain crops is amply remunerating, though

* As of Lower Wyanoke, Shirley, and Curie's Neck, in vol. i. ; Westover,
in vol. i. ; Sandy Point, in vol. ix. ; Brandon, in vol. x. ; besides many
other slighter references to these or other similar lands.

232 ANCIENT ALLUVIUM Oil LATEST DRIFT FORMATION.

still falling mucli short of what it will reach some year« later. All
these fine lands, on James river (owing to their fresh-water allu-
vial formation), are destitute of the marl (of fossil sea-shells),
which is so generally abundant lying under the adjacent higher
lands. Still, nearly all have been covered either by marl water-
borne from other places, or by lime brought from Pennsylvania, or
burnt from purchased oyster-shells. The percentage of increase
in the crops, even after the full effect is produced by calxing, is
much less on these lands, than of the poorest acid soils. But the
absolute increase of crop, and also the profit compared to the ex-
pense of the manuring, on these neutral and especially the hazel or
*^ mulatto" soils, after some years, are as great as the absolute in-
crease of product, and the profit, on any acid or other poor soils.
The original production, and even the much reduced production of
these best soils, was so much higher than that of acid soils, that
an improvement of 50 per cent, in the crops of the former may
well be a greater absolute increase and profit, than an increase of
100 or even 150 per cent, on much poorer lands.

On all the other tide-water rivers of Virginia, there are flat
lands of like geological formation, and having general resemblance
to those of James river ; while all such, on each different river,
have still more of general similarity of character to each other,
and of general difference from such lands on other rivers. Such
results might be inferred, from the great sources and materials of
the ancient alluvium having been different on each of the rivers.
Such lands on the Pamunkey river are the most extensive, the
most elevated (being in most cases full 30 feet above the present
level of the river, and far above the highest freshes), and also the
most valuable. Not much of this land is as clayey or was as rich
originally as the smaller extent of best lands on the tide-water of
James riv^r. But for ease of tillage, and cheapness of improve-
ment by marl, and for profit on the capital and labour employed,
no lands are superior. Since the beginning of 1844, I have been
a proprietor and cultivator of a farm of this description, bordering
on the Pamunkey (Marlbourne) ; and within the next seven years,
applied marl to the amount of nearly 370,000 bushels. The in-
crease and profits therefrom have already much exceeded my pre-
vious expectations ; though both (from the lateness of the manur-
ings) are still much below the mark they will reach, when time
enough shall have passed to bring the manure into full operation. It
is proper, however, to state that the marl used on the Pamunkey flats
is the green-sand eocene — of peculiar character, and of more
than the beneficial operation of mere calx, or carbonate of lime.
It is indeed not rich in calcareous earth (having from 25 to 30,
and very rarely 35 to 40 per cent.); but, in addition, it contains
Bome gypsum, and a considerable proportion of green-sand. And,

ANCIENT ALLUVIAL OR LATTER DRIFT SOILS. 233

judging from the effects as manure, it seems probable that some
phosphate of lime is also present. By these auxiliary ingredients,
added to the main source of fertility, the calx of the manuring
earth, the vigour and luxuriance of clover is peculiarly promoted —
beyond any effect of calxing alone known elsewhere — and the
succeeding wheat crop is also increased in proportion to the clover-
manure grown and turned under to prepare for the wheat.

Some small portions of the Pamunkey flats are of close and im-
permeable pale yellowish clay, and the value much the less fbr this
objectionable quality. But most of such lands are of light sandy
loam, and some very sandy. Some of the sands are of mulatto
soil, and some gray, and even approaching to acid character. No
red clay soil, or sub-soil, is there known.

It has been deemed proper to speak thus fully of these neutral
soils, and their improvement by calxing, because the circumstances
serve most clearly to establish the opinion stated formerly (in the
edition of 1842), that calcareous manures must possess some other
and important fertilizing action, besides the several kinds before
asserted (in Chap. VIII.). Of these several powers, neutral soils
did not require, and therefore could not profit by that of neutraliz-
ing acids ; nor of altering the texture, absorbency, &c., of the soil.
Such soil had already been provided by natural constitution with
enough lime for these purposes. Therefore, the only other fertiliz-
ing property there claimed, in advance of experience, for calcareous
earth, that of combining with, preserving, and fixing putrescent
manures in soils, was all that could be counted upon to improve
neutral soils. But this slow and merely conservative action, how-
ever valuable for improvement, could not possibly be the sole cause
of the great and progressively increasing production of neutral
soils, which was manifest within a few years after their being
calxed ; and other and important causes had evidently been operat-
ing. And although the circumstances of neutral soils led more
immediately to this conclusion, those of the acid soils also con-
curred. As was intimated in former editions, on all soils and crops
which were improved by calcareous manures, though the expe-
rienced effects were strictly in accordance with the theory of their
operation, they seemed in measure and amount to surpass their
supposed causes. I will now proceed to set forth other auxiliary
causes of fertilizing action and power of calcareous earth, or lime
salts generally, in soils ; which causes have been suggested by or
deduced from the more recent lights furnished by the progress of
the science of agricultural chemistry, and in part are the results
of my own later observations or experience. The most important
of these additional powers or operations of lime in soil arc the
following ;

20*

234 SOLVENT ACTION OP CALX.

I. Causing the more rapid decomposition and perfect solubility
of vegetable matters, otherwise inert or insoluble.

II. Enabling either the soil, or the plants growing thereon, to
draw from the atmosphere greater supplies of manuring or aliment-
ary principles, viz. :

1. Carbon, to growing plants;

2. Azote (nitrogen), from the atmosphere, through the instru-
mentality of leguminous plants;

3. Nitric acid, and nitrates, to the soil, and thereby increasing
the supplies of azotic principles to growing plants.

III. Giving to all growing plants a more healthy constitution,
and more vigorous vital powers, and thereby more ability to with-
stand dangers and injuries of all kinds.

These several branches of the subject will be discussed in the
following pages ; and so far as they admit of separation, in the
order stated.

§ I. Lime and Carbonate (and other Salts) of Lime render Ycge-
table and Organic matters more soluble.

It is a well established chemical action of the fixed alkalies pro-
per (potash and soda), on vegetable or other organic matter, to render
it more soluble, and thereby more speedily and effectually to reduce
insoluble and inert organic manures to the state fit to be taken up
by the roots of plants ; and enable them to be more completely
consumed as food for plants. It may well be inferred, from the
general resemblance of chemical properties, that this solvent action
of the alkalies proper must also belong to the alkaline earths, lime
and magnesia, even though in combination with carbonic acid
That caustic or pure lime exerts this solvent power was stated
previously (page 103), when treating of its manuring action. Like
effects, as exhibited in the rapid disappearance of leaves, &c., on
calcareous and neutral soils, were also stated (page 98), from which
effects it might be inferred that this solvent power attended lime in
all its ordinary combinations or conditions in soil ; though perhaps
then exerting this power more slowly than either caustic lime, or
carbonate of potash. These well-known eff"ects on natural soils,
and also the quicker and better effects of unrottcd putrescent ma-
nures when applied to calxed lands, I had ascribed altogether to the
indirect action of calcareous earth, in its having neutralized the
previously existing acid, which was antiseptic, and prevented or
retarded the rotting and solubility of the vegetable matters. But
besides this indirect action, there seems good reason to believe that
there is also a direct solvent power exerted by salts of lime, similar
to that of the alkalies proper, and their salts, or combinations with
acids. Ilennie and Thaer have expressly extended this known
chemical action of the alkalies proper to the alkaline earths, even

ALLEGED IMPOVERISHMENT BY CALXING. 285

when in the state of carbonates.* That such extension is correct
is further confirmed by some of the effects of calcareous manures,
as adduced by Prof. Johnston, and as understood by practical
limers in England. He says, of the action of lime, " it changes
the inert vegetable matter in the soil, so as gradually to render it
useful to vegetation (p. 400) ; and further (p. 401), that ^' under
the influence of lime, the organic matter disappears more rapidly
than it would otherwise do ; and that, after it has thus disappeared,
fresh additions of lime produce no further good effect.'' These
results, in substance, have been maintained in the preceding por-
tion of this essay ; but were ascribed there to other than the gene-
ral solvent action of calcareous earth — which I would now suppose ,
to be one of the important concurring causes.

According to the treatment of the land while this solvent action
of calx is proceeding, through a course of years, the general and
final results will be either injurious, in the removal and destruction
of the organic matter (as stated by Johnston), or beneficial, by its
being stored up and fixed in the soil, under reverse circumstances.
If .the system of cropping be continually exhausting — taking as much
as possible from the land and returning nothing — then the lessen-
ing and disappearance of the organic matter, whether slowly or
speedily, will finally be complete ; and equally sure will be the so
induced and almost hopeless subsequent sterility of the soil. It was
upon such ignorant and destructive cropping as this that was
founded the often quoted old proverb in England, that " liming
makes rich fathers and poor sons.'' And this saying will be cer-
tainly true, if understood of liming (or of calxing in general),
followed by continued or generally exhausting tillage ; though en-
tirely false if followed by mild meliorating cultivation, and judi-
cious management. Doubtless there were formerly in England, in
times of ignorance and bad farming, numerous cases of the destruc-
tive results of calcareous manures; and it is much to be feared,
that, from as ignorant practice, and at some time hence, there will
be many such results in this country. Some such have already

* Both passages have before been quoted, in reference to other subjects.
Rennie says of insoluble humic acid, that it "readily combines with many
of the substances found in soils and manures, and not only renders them,
but itself also, easy to be dissolved in water, tvMch in their separate state could
not take place. In this way humic acid will combine with lime, potass,
ammonia, in the form of humates, and the smallest portion of these [alka-
line matters] will render it [the humic acid] soluble in water, and fit to be
taken up by the spongelets of the root fibres." — {Alphabet of Scientific Gar-
dening. )

Thaer says — " It is well known that with the aid of alkalies, ashes,
lime, and marl, humus may be deprived of its acidity, and rendered easily
soluble.'' (p. 538.)

236 MANNER OF CAUSING STERILITY.

been produced; and many more are in progress, in spite of all
warnings of the danger.

Tliougli Johnston uses the word ^^ lime'' alone in the above pas-
sages, or in immediate connexion with them, it is evident from his
context that he meant carbonate of lime, or such condition as lime
would be in some years after its having been applied as manure ; and
this condition would certainly not be that of caustic or pure lime.
If admitting to the fullest extent the solvent action claimed according
to his views, the extreme cases would stand thus : The unrotted
and then insoluble organic matter in a soil, which, without calxing
the land, might require (suppose) twenty years gradually and
slowly to become soluble and fit for use, and to be used by plants
as becoming fit, might otherwise become soluble and as fit for feed-
ing plants in the course of ten years, if in soil made calcareous.
In the former case, the most relentless exhausting tillage could not
totally consume or remove all the organic matter in less than twenty
years, because it could not be used or exhausted before becoming
soluble. In the latter case it might be done (possibly) in ten
years, admitting the extreme deduction from Johnston's views; or
according to mine (if allowing for the preservative as well as the
solvent operation of calx), all the first existing organic matter
might be used, and the land made sterile, say in fifteen years.
Supposing further, to be produced but an ordinary increase of crops
from the calxing, then the total products even in the ten and fif-
teen years respectively required to reduce the land to a state of
unproductiveness would amount to twice or thrice the amount that
could have been obtained in twenty years from the land if not
calxed. Thus, even in such extreme and similar circumstances of
unmitigated exhausting tillage, the advantage in profit would still
be greatly in favour of the calxed land.

But why should we waste arguments or words on such supposed
cases of absurd and destructive tillage, pushed to the extremity of
reducing the land to barrenness ? Whether land be limed or not,
a continued exhausting course of tillage, even with some, but in-
sufiicient intermission, can only, sooner or later, lead to the same
result of the greatest possible exhaustion, and with certain eventual
loss to the proprietor.

Even if nothing be allowed for the important preservative action
of calx (which in truth would hold and fix all the. organic matters
made soluble, until they were used by growing plants, however
long that use might be deferred), still I would deny that the sol-
vent action of calcareous manures would be of itself destructive or
injurious to the future productive power of the land. It is indeed
true, that the fertilizing elements thus offered so readily (by earlier
solution of inert vegetable matters) might be so much the more
readily wasted and exhausted by an ignorant and improvident cul-

BENEriT OP LENIENT CROPPING. 237

tiyator. But on the other hand they might as readily be used
profitably, in part reinvested, and increased by partial accumula-
tion, while still producing good profit, by judicious farming. If a
merchant's capital, in ships, warehouses, and merchandise, could, at
any instant when desired, be converted, partly or wholly, to the value
in ready money, surely no one would deem that facility as other
than an immense advantage to his business and means for increas-
ing his wealth. Or suppose that the merchant's trade with remote
countries, usually requiring three years to return his ventures and
the profits, could, by some change, bring the like returns every
three months ; would any one contend that this more rapid ^^ turn-
ing over his money" would be a loss to him ? Yet both facilities
would enable him, if so inclined, so much the sooner to spend his
income and his capital stock. Just so, and no more, is the farmer's
land necessarily to be exhausted, or his total income and capital
spent, because calxing has enabled him to obtain a certain amount
of income in half the time previously required; or even to draw out
his whole landed capital in annual income, and to waste the whole,
if he is so foolish a prodigal as to take that course.

In truth, if but a small proportion of the new products, or in-
crease created by calxing, be given back as manure to sustain the
productive powers of the land — whether in prepared putrescent
manures, or in green crops used as manure, or merely by giving
rest, and the natural growth during rest to be left on the land — so
that the draughts from the land will be less than the supplies fur-
nished to it from all sources, there will be no continued exhaustion
even in the slightest degree, no diminution of average products —
and the sons, no less than the fathers, may be made rich by the
operation of lime.

On all cultivated lands, whether rich or poor, calxed or not,
proper considerations of farming profit alone would require that the
crops should take no more of fertilizing principles from the land,
than are restored, and exceeded, if possible, in the returns made to
the soil. In making these returns, bountiful Nature adds three
and four-fold to all that the farmer can give in manure or other
improvement. The earth, water, and the air, are all continually
preparing and furnishing manuring principles to the soil and to the
crops. The richer and better constituted the soil, or the more it is
enriched by putrescent manures and rest, the more, and in a far
increased proportion, does Nature furnish in addition, other aids
to resuscitation or increase of fertility. Hence, the more that
the fiirmer gives to the land, the more, and in increased pro-
portion, will it return to him. Therefore, it is no certain course
of cropping, and of intermission or melioration, that can be stated
as always improving the fertility of land, or otherwise exhausting
it. The results of a certain rotation may be improving to a good

238 BENEFIT OP SUPPLYING VEGETABLE MATTER.

and rich soil, and yet would be exhausting to a bad and poor one,
A good and rich soil may, in some cases, yield three crops of grain
in four years, and yet improve by the rest and self-manuring (by
its own vegetable growth) of the fourth year only — while very poor
land may not increase its scant products, though cropped but one
year in three. Yet the rule of resuscitation, and its working, are
alike in both cases. The one-fourth of the product of the best
soil serves to give it more manuring, even in proportion to all its
large crops removed, than two-thirds of the whole product of the
poorest soil, in proportion to its very small yield for consumption
and sale. This greater supply of fertilization to a good soil in
shorter time is not altogether in the mere quantity of vegetable
matter furnished. The greater part probably is due to the superior
power of a lime soil to fix and so retain the enriching products of
vegetable decomposition, which, on an acid soil, wanting this fixing
power, would be mostly wasted. This is another illustration of the
important economy of calxing all lands not abundantly supplied
with lime by nature.

The allowing to land, after having been marled or limed, a due
share of rest from tillage, so as to permit its being manured by its
own growth during the times of rest, even if not essential, would
be one of the^most important of the accompanying benefits to the
farmer ; for by such means of furnishing the necessary supply of
organic or putrescent matters to the soil, the same value of manur-
ing is given at very far less expense than if by manures artificially
prepared in the stables and barn-yard. Highly valuable and im-
portant as are the latter, and more especially profitable to the
calxing farmer, still their amount is limited by the measure of both
the supply of materials and of labour to be given for preparing and
applying the manure. But to manure a field by its own growth,
requires very little more than to let it alone. If merely left a year
nntilled and ungrazed, an important gain is secured without any
cost of labour or material. And if, as part of a proper rotation,
to the resting there is added the seeding of the land in clover, or
any suitable leguminous growth for green manuring, the additional
benefit will be much more than the additional expense.

This essential and also highly profitable accompaniment to
liming or marling is precisely the condition which is most gene-
rally objected to by those who wish to begin such improvements —
and the most frequently neglected by those who have already
limed or marled. In the reasoning of the one class, and the prac-
tice of the other, it seems to be required that calxing shall do
everything for fertilization and production, without aid, and be
proof against all powers of exhaustion and destruction by tillage.
And if such unreasonable demands be pronounced impossible to be
complied with, it serves with many as sufficient ground to deem

ERRONEOUS PRACTICE IN SOUTH CAROLINA. 239

the use of calcareous manures unprofitable ; or if already used, to
charge to them the subsequent deterioration or exhaustion of
the land which had been allowed neither sufficient rest, nor returns
of putrescent matters.

In the year 1843, when acting as Agricultural Surveyor of South
Carolina, my most earnest effort was to induce the planters to make
proper use of marl ; which is there more rich, more abundant, and
more easy of access through a large portion of that state than a
stranger can well conceive, and of which almost no use had then
been made. Gov. Hammond and a few others made the only ex-
ceptions to this general neglect ; which cases of exception were
stated in the " Report of the Agricultural Survey of South Caro-
lina." My failure then to persuade more than a few planters to
try this richest and also cheapest of means for fertilization, and
the neglect to use these means which still continues very generally
in South Carolina, were mainly owing to the required condition of
giving due rest and vegetable growth for manuring to the marled
lands. This condition I always and strongly urged as essential ;
and it was so contrary to the general system of tillage there in
use, and therefore was deemed so objectionable, that but few persons
were willing to make the required change for any expected benefits
from marling. Nearly all who before or since have there tried
marling, have failed to add these necessary accompaniments ; and
of course their early returns have not been half what they would
otherwise have been, and the ultimate results will be still more
deficient.

The general usage in South Carolina was to take a crop for
market or consumption (generally either cotton or corn) every
year. As there was no other than tillage land (arable, and not
before worn out), if a planter were to spare a field, or any smaller
space from culture, it would be equivalent to losing just so much
of his usual crop and income, for that year. This was deemed a
sacrifice which very few were willing to make, and none to suffi-
cient extent. It is true that new clearings, where there was forest
land to clear, were added every year to the tilled land. But this
additional surface was required (as supposed) either to substitute
the older land utterly worn out, and turned out of culture, or
otherwise to serve for the planter's increased means for labour.

This very bad usage of continual tillage was indeed made the
less exhausting, and the more tolerable, by a system of collecting
and applying vegetable manures, admirable for the energy with
which it was pursued, and for the great extent to which it was
carried. I have never known so much of the labour of farms to
be devoted to making and applying putrescent manures, nor so
much of the tilled surface to be so manured, as in lower South
Carolina. For this purpose, large stocks of cattle are kept (in

240 NEED FOR VEGETABLE MANURES.

very poor condition indeed), and vegetable matter in great
quantity is gathered in leaves from the wood-land, and sedge and
rushes and other growth of the tide-marshes, to be used as litter.
The manure is applied in the row or drill, so as to go as far, and
act as quickly, as possible. This large but slight and poor manur-
ing required frequent renewal ; and by some planters it was re-
newed every year over their whole extent of cotton, which was
much the largest of all the tilled surface. All these efforts barely
served to keep up the manured land to its previous moderate rate
of production ; and if that could be done, the planter was content
to make no absolute or abiding increase of fertility by his continual
applications of wasting and fleeting manures. When urging on
such persons the use of marl or lime, I was frequently met by the
question " Will marling enable me to dispense with other ma-
nuring ?" and the negative to that question, always promptly given
in answer, was generally assumed as sufficient reason for failing to
use calcareous manures. Yet never was there a greater mistake,
or more false reasoning, than led to this conclusion.

Besides all other benefits to be gained by thus improving the
constitution of the soil, marling would have made half the usual
dose of putrescent manuring do more good than the whole. By
giving rest and its own self-manuring, say to one-third of the arable
surface, the other two-thirds would soon surpass the previous pro-
duction of the whole. And much more crop would be obtained
both from the land and the labour employed, than before marling
and resting, or than with marling and without resting, besides a
continued growing increase of fertility and production.

But the idea of even the present gain of a proprietor being made
the greater, or the early lessening of crops being avoided, by con-
tinual culture, is entirely fallacious. The renter of another's land,
for one or two years only, may indeed reap most crop and profit
by tilling the whole surface. But his successor will lose in pro-
portion to the previous excess of cropping. So the man who hires
a horse for a day only may get from him the greatest quantity of
labour and at least expense, by working him the whole time, with-
out food or rest. But it is as true economy and profit to allow
food and rest to the land in an occupancy of but a few years, as to
the horse if employed but for a few days. In either case, the ex-
pense of such allowance is an investment which will return a
higher rate of profit than all that could be gained without such
expense.

Further : unless when the application of putrescent manures is
very frequently renewed, and therefore is very expensive, the
resting of the land is not the less certain to occur, and for as long
intervals, as if allowed by the most lenient rotation of crops. In
the latter case, perhaps the land (after being calxed) yields three

PROFIT OF REST TO LANdT 241

gram or otiier crops for market in a five-years rotation; tlie other
two years being given to rest, self-manuring by the vegetable
growth remaining, or part of the land being in pasture. With
such respite, the three-fifths of the land will very soon surpass the
previous product of the whole, and continue long to increase still
more in product. In the other case, of continual annual cropping,
and even with much care given to applying prepared manures, the
land may perhaps bear such treatment for twenty, thirty, or in rare
cases forty years, before being so reduced as to be no longer worth
cultivating. It is then ^^ turned out," and left useless and profit-
less for some thirty years, until, under a new growth of trees, it is
brought back partially to a state fit for a second and expensive
clearing, and renewed cultivation. Nature will not permit the soil
to be utterly robbed of its due claim "for rest and resuscitation.
And if the cultivator will not of his own accord grant one or two
years in four or five, he will be compelled to lose a much larger
proportion of time, after longer delay. In the one case, the rest
is accompanied by increasing fertility ; in the other it is the result
of exhaustion, and is followed by long-continued and total unpro-
ductiveness.

The amount of rest for land required for its progressive improve-
ment after being marled, after all, is inconsiderable, and is, usually,
fully compensated in the greater product of the two next succeeding
crops of grain. In lower Virginia, the system of continual tillage
formerly was as prevalent as now in South Carolina. Yet there
are very few of even the most improvident and exhausting cultiva-
tors who do not now know that more grain and more profit are to
be obtained in a three-years course (for example), including one
year of rest, than if taking a crop every year. And on calxed and
well conducted farms, making regular advances in production,
three grain-crops and one of clover are taken off in a five-years'
rotation, leaving but one year of the term in which the land is un-
productive of profit for that time — though not unproductive in
preparing for future returns.

Whether the question be considered and tested by facts and ex-
perience, or by reasoning, there cannot be a shadow of reason or
excuse for the custom of continual tillage, except in a newly settled
and uncleared country, of great fertility, and where labour is very
costly, and land priced very lew. Not one of these conditions now
exists in lower South Carolina to justify the general system of till-
age. And that so intelligent, well educated, and withal so indus-
trious a class as is found in the planters generally of that state,
should so strangely persist in such a system, and, for its preservation,
reject the means of doubling their products and their wealth by
marling, is not the result of the teachings either of reasoning or
of experience, but of the supremacy of habits long established,
and in almost universal use.
21

242 ELEMENTS OP PLANTS.

§ II. Calcareous earth enahles the soil, or the plants growing
thereon, to clraio much more nutriment from the atmosphere.

Every plant, after being completely burned, leaves a small pro-
portion of its previous quantity in ashes. This portion, inde-
structible by burning, is distinguished by chemists (not with much
accuracy of signification) as the inorganic parts of plants ; and
these are found to consist of different salts, or chemical compounds
of different acids with alkalies proper, and alkaline or other earths,
and also some oxides of metals. All these matters, making the
whole residue in ashes, in any one plant, or part or product of any
plant, rarely amount to as much as one-tenth of the original dry
weight ; and in more of other cases fall below the one-hundredth
part.*

The other and much larger portion of all vegetable matters,
called by chemists the organic, or that which is destructible by
burning, is composed either of three or most generally all four of
these elements, carbon, hydrogen, oxygen, and nitrogen or azote.
The like division of products, desti-uctible or indestructible by
burning, applies to all animal matters, and also the general consti-
tution of their different parts ; but in very different proportions.
Excepting the solid bony or shelly parts of animal matters, the
portion indestructible by burning is extremely small. Of the des-
tructible parts of animal matter, azote (or nitrogen), always forms
a considerable proportion ] while in most vegetable products it is
in very small proportion, and in others entirely wanting. It is,
however, always present either in some ptirt, or element, or pro-
duct of every plant. It is the proportion of azote, small as it is,
which mainly determines the degree of richness and nutritive value
of any substance, whether as food for animals, or as manure for
growing plants. And according to the quantity of azote contained,
is the tendency of either vegetable or animal matter to putrescence,
and to give out offensive odours while putrefying. Thus, in a rough
way, common observation and experience, and the sense of smell,
may afford tolerably accurate tests of the amount of azotic prin-
ciples in materials of manures for plants, or food for animals.

It follows from the consideration of the questions of which the
general results only are here stated, that whatever serves to furnish
most azote to the soil, in manure, is most conducive to its immediate
fertility ) and whatever abstracts mo^ azote from the soil, without
return, is the most exhausting of its immediate productive powers.
Having presented these general propositions (which seem to be
received by all authorities), let us proceed to inquire as to the
sources of the mode of supply of azote, and of the other much
more abundant constituents of plants.

* See tables of proportions for ashes from many vegetable products re-
ported by BouiiSingault, p. 53, 4, llurul Ecouomy, Am. Ed. of Eng. Trans.

ELEMENTS 01' PLANTS. " 243

Patting aside for tlie present the minute proportion of inorganic
elements (or ashes) of plants — or supposing their amount to be
always ascertained separately, or understood — the great remainder
of all plants, amounting from more than nine-tenths of the dry
weight of some products to more than ninety-nine-hundredths of
others, consists of elements which also constitute air and water, or
are always present in the atmosphere ; and which therefore are
always surrounding all growing plants, and in unlimited quantities.
But though so abundant and inexhaustible, these elements cannot
be taken up by growing plants except under certain conditions j
and these conditions are but slightly under the control of cultiva-
tors, or even known to the present researches of science.

Of the four great elements of organic bodies, carbon only ia
ever presented to our senses, alone and as a solid. Charcoal is
nearly pure carbon; and the brilliant and precious diamond *is pure
crystallized carbon. Of the three other great elements, oxygen,
hydrogen, and azote, each one in its separate state is only known
to us as gas, or air; and however different and potent their quali-
ties, they are all as little perceptible by our sight or touch, as the
atmosphere. Further : carbon, though existing nearly pure, and
visible and tangible, as charcoal, yet, when in that state, is incapa-
ble of affording any direct support to plants ; for which office it is
necessary that carbon shall be combined with oxygen ; which com-
bination also forms a gas (carbonic acid), in which state it is dif-
fused throughout the atmosphere, and in which only it is fit to be
received into plants, through their leaves, and thus to furnish to
them their essential element, carbon.

Thus, the materials of nearly the whole solid substance of all
plants and all animal bodies, are supplied wholly by four gases, or
different kinds of air. This proposition (than which none in agri-
cultural chemistry is better established), when first heard, may
well seem too mysterious for comprehension, and the results too
wonderful for belief. And after -the proposition has been fully
assented to, there must occur to the mind of every student of this
interesting subject another question involving as much of mystery
and wonder, if not also of doubt. This question is, ^^If the
atmosphere always contains all the organic constituents of plants
in inexhaustible quantities — and if plants derive from the atmos-
phere nearly all of their constituent parts — why should they ever
suffer for want of a sufficient supply of nourishment, whether
growing on rich or poor soils V The answer is, that the laws of
nature forbid some of these gaseous bodies to be taken up directly
by growing plants — or, at least, only under certain conditions ;
and these conditions are not dependent on the quantities of these
gases present in the surrounding atmosphere, and are but slightly
under the control of man^ limited in knowledge as at present.

244

' ORGANIC AND INORGANIC PARTS OF PLANTS.

Should the progress of science ever serve to place these conditions
under man's control, then exhaustless stores of the richest nourish-
ment to plants, and the sure means of universal and exuberant
productiveness from the poorest soils, will also be at his command.
Food for land and plants and brutes and men will be as unlimited
and almost as available as the air we breathe. But to indulge in
such speculations of the possible future, is now mere dreaming
anticipation. My object is more practical. It is to gather and
display such faint lights as now may be drawn from previous
scientific researches upon this dark and yet interesting subject of
inquiry. As little as has been discovered and established by agri-
cultural chemists, and still less put to practical use, I believe that
new and very important and useful deductions may be derived fi'om
the scattered and unconnected truths already ascertained in regard
to the nutrition of plants, and, through the medium of plants, the
nutrition and fertilization of soils.

The following table is given by Boussingault as the results of
his investigations, showing the proportions of the constituent
elements of various ordinary vegetable products.

Substances— dried at 230° Fahr.

2

1

^

100 parts.

^

1"

?

o

- -g

6

a

o

<

■<

Wheat

46.1

05.8

43.4

02.3

02.4

Rye

46.2

05.6

44.2

01.7

02.3

Oats

50.7

06.4

36.7

02.2

04.

Wheat straw . . #- .

48.4

05.3

38.9

00s 4

07.

Rye straw

49.9

05.6

40.6

00.3

03.6

Oat straw .....

50.1

05.4

39.

00.4

05.1

Potato

44.

05.8

44.7

01.5

04.

Field beet

42.8

05.8

43.4

01.7

06.3

Turnip

42.9

05.5

42.3

01.7

07.6

Jerusalem artichoke (or potato) . .

43.3

05.8

43.3

01.6

06.

Peas

46.5

06.2

40.

04.2

03.1

Pea-straw

45.8

05.

35.6

02.3

11.3

Clover hay ...

47.4

05.

37.8

02.1

07.7

Jerusalem artichoke stems .

45.7

05.4

45.7

00.4

02.8

From these propositions of the vegetable products stated, it
would appear that the per centage of each of its elements is be-
tween the following extremes :
i Carbon from
Hydrogen
OxygeS
Azote
Inorganic parts — Ashes

Of the first-named four and sreat constituent parts, carbon

42.8

to 50.7 per cent

5.

to 6.4

85.6

to 45.T

00.4

to 4.2

2.4

to 11.3

great

constituent partS;

ORGANIC PARTS OF PLANTS. 245

only is famished by nature otherwise than in the greatest profu-
sion. Oxygen gas makes about one-fifth, and nitrogen or azote
about four-fifths of atmospheric air ; and pure water is a compound
of 8 parts of oxygen and 1 of hydrogen. Carbon in the form
of carbonic acid gas is universally present in the atmosphere, and in
variable proportions ; but usually (over land) making about ^j^q^
only of the whole bulk. In weight, the proportion of carbonic acid
is jono ^^ ^^^ atmosphere. Small as is this proportion, still, as it
is present in the air surrounding and iji contact with all growing
plants, their supply might be deemed inexhaustible, provided they
possessed the power of attracting and arresting it, and taking up
and assimilating the carbon of the gas. But this power seems to
be not fully exerted under ordinary circumstances. The other
great el-ements, oxygen, hydrogen, and azote are in unlimited
quantity surrounding plants, as constituents of the atmosphere, or
entering and filling the bodies of plants as the constituents of wa-
ter. And as the atmosphere always contains, in large proportion,
water dissolved by heat, that is, the water itself being in gaseous
form, therefore the ordinary atmosphere alone offers to plants all
the four great elements required to constitute nearly their whole
substance. If then we suppose that the very small proportions of
necessary salts, found in the ashes of plants, are already in the
soil (as is generally the case), or, if not naturally present, to be
supplied by art, it is manifest that all cultivated plants, on all
soils — and on the most barren not appreciably less than on the
richest — have at hand unlimited supplies of all materials required
for their sustenance and growth. But the power to seize upon
these materials is either wanting, or possessed but to a strictly
limited extent. And it is in proportion to the power to use them,
and not to the abundance of the resources present, that the sup-
port and growth of plants are regulated.

The proportions of the atmospheric constituents of each particu-
lar vegetable product (as gluten, starch, sugar, wax, &c.) seem to
be uniform ; and of each of the more compound products of a par-
ticular plant (as its seeds, flowers and leaves, bark, wood, &c., of
like age and kind), the constituents seem to approach uniformity
of proportions ; so that it may be inferred that the difi'erences are
caused by differences of conditions, of wants and supplies; and that,
under like conditions, the constituents, organic and inorganic, would
be in like propositions. But the quantities of the simpler pro-
ducts of plants of like kind (as gluten or starch in wheat, sugar
in beets, &c.) vary greatly, and of course cause variation in the
proportions of elementary constituents of the entire plant. Es-
pecially does the proportion of azote vary in like plants, under
different circumstances of supply, even when the other constituents
vary but little. Boussingault found the following proportions in
21*

^46 NITROGEN IN PLANTS.

wheat of the same variety, but of which one sample was taken
from garden ground, very rich, and the other from the ordinary
soil of his field, and of course comparatively poor. The growths
were of the same year, and the same farm, and therefore the influ-
ences of weather the same.

'from the open fielb. from the garden ground.

45.61

. 5.67

43.00

3.51

2.31

Carbon,

46.10

Hydrogen^
Oxygen, .

Azote, .

. 5.80

43.40.

. 2.29

Ashes,

2.41

100.00 100.00

"In the produce of the garden ground there were 21.94 per
cent, of gluten and albumen [the products of wheat which only
contained azote] ; in that of the open field no more than 14,31 per
cent, of the same principles. '' — {Rural Economy, &c., p. 176.)

The cursory reader would perhaps be struck only by the general
agreement of the proportions of the constituents of these two
samples of wheat grown on such difi'erent soils. But while there
is such near approach to equal proportions of the three larger con-
stituents, the azote, smallest in quantity, but the most important
for its quality, is shown to be increased in proportion more than
50 per cent, by the richer soil.

Thus the smallest but richest element, azote, would seem to be ob-
tained by plants principally or entirely through their roots, and from
the soil. Therefore, the supply to plants is in no degree increased by
the prodigious quantity of azote in the atmosphere. On the other
hand, the carbon, which constitutes about half the dry weight of
all plants, is supplied, for much the larger part, from the carbonic
acid gas of the atmosphere, through the leaves, and thus is fixed
in and assimilated to the plant. Carbon is the only one of the
four great elenLents found in air or water which is presented (by
the atmosphere) to plants in small quantity, and apparently in in-
sufficient quantity for the supply of their leaves. Therefore, I
infer that to increase the nourishment and growth of plants it is
not only necessary to increase the supply of azotized manures
through the soil to their roots, but also (if possible), to increase
the supply of carbonic acid to the leaves; or to increase their
power to take up the supply actually present in the surrounding
atmosphere.* As to the oxygen and hydrogen, they will be sup-

* Professor Liebig maintains that all the azote taken up by plants is
through their roots, and of course derived immediately from the ^ soil.
Boussingault infers, from some very interesting experiments, to which I
shall again advert, that some azote is also taken directly from the atmos-
phere, at least by leguminous plants. The latter author, agreeing with

SUPPLY OF ORGANIC PARTS TO PLANTS. 247

plied from tlie air and water in any quantities required in propor-
tion to the amount of carbon and azote derived from all sources.
Chemists seem to concur in the opinion that plants exert the power
to decompose water received through their roots into their sap
vessels, and to assimilate the results of the decompositiouj hydro-
gen and oxygen, in requisite proportions. Besides all other reasons
in support of this opinion, its truth may be inferred from the
established fact that in many vegetable substances the constituents
of hydrogen and oxygen are present in precisely the proportions
which serve to constitute water.

If then enough azote and carbon be furnished to growing plants,
enough of oxygen and hydrogen will be at the same time taken up
and assimilated, by the plant's own natural powers.

The foregoing views seem to offer the only plausible explanation
of that great mystery of vegetable life, that plants on barren land
should pine or starve, when surrounded by unlimited supplies, in
air and water, of their necessary elements.

The supply of azote to the roots must be limited to the amount
of azotized matters already in the soil, and to such subsequent
additions as can be furnished in prepared putrescent manures, or
in the azotized green or dry products of the land left there to de-
cay. If we could also increase the supply of carbonic acid in the
atmosphere, the benefit to plants would be as great as the giving
of azote in manure. It has been proved by experiments, that of
different plants kept in confined artificially composed atmospheres,
those grew best, which had carbonic acid in much larger propor-
tion than is in the natural atmosphere. (Boussingault, p. 36.)
To increase the quantity of carbonic acid diffused through the
atmosphere, to any useful or even appreciable extent, is beyond the
power of man. But the desired results of such increase would be
reached in some measure by enabling plants to inhale and assimi-
late more than their share of the general supply of carbonic acid
in the whole atmosphere. This is partially effected for all vegeta-
ble growth b^ the winds, which continually renew the air in con-

most other late and high authorities, supposes the carbon of plants to be
derived principally from the atmosphere, and through the leaves, but also
in part from tlie earth and through the roots. Liebig asserts that carbon
is furnished altogether through the leaves, except during germination ; and
none through the roots, after the opening of the earliest leaves from the
seed. This opinion seems to involve the absurd position that the carbona-
ceous (dark-coloiu-ed) part of manure, usually deemed evidence of richness
in manure and in soil, is of no use to plants through their roots ; nor
otherwise, except to furnish more carbonic acid to the atmosphere. In this
event, the manure, by its carbonaceous part, may possibly assist the
growth (through the leaves) of the plants growing nearest. But if any
wind was bloAving when the gas rose from the earth, the manure would be
as likely to take effect on distant as on the nearest plants, even if not car-
ried out of reach of all for the time being.

248 SUPPLY OP CARBON TO PLANTS.

tact with plants, removing that which had given up its carbonic
acid, and bringing new supplies from the upper or lower air. It has
also been proved that plants grow faster in agitated than in still
air. (Boussinganlt, p. 42.) This effect of winds is general — ope-
rating with nearly equal benefit on all neighbouring localities ; and
this also of course is not within man's control, or even under his
partial direction.

There is still another mean, by which possibly the desired end
may be attained. Though we cannot increase the supply of car-
bonic acid, or bring more of the actually existing supply in con-
tact with the leaves of plants, yet if we can stimulate the plants to
attract, seize upon, and rapidly absorb the contiguous carbonic
acid, instead of the much greater- part passing by and escaping from
the otherwise feebler attracting powers of plants, then the same
object would be effected as if by actual increase of the supply of
carbonic acid. There is good reason to believe that such greater
stimulation of the appetite of plants and increased power of taking
up carbonic acid is to be conferred by the application of vatious
manures ; but more especially and in greater measure by the use
of calcareous manures ; as I shall endeavour to show.

Universal as is this function of growing plants of absorbing and
fixing the carbon of the atmosphere — essential as it is to their
existence — and largely as it is exercised to the extent of thereby
obtaining much the larger part of one-half the whole dry weights
of plants — still this power is strictly limited by, or only exerted
under, certain known conditions. It is by their green matter only
that plants absorb carbonic acid, and that under the stimulating
influence of liglit. Through all the day, and by all their leaves
and other green parts, plants are absorbing carbonic acid from the
air, and assimilating and fixing its carbon, and evolving the oxygen
gas, the other constituent element of the carbonic acid. But this
operation always ceases with the withdrawal of light ) and even a
reverse operation, to smaller extent, proceeds during the night,
when the leaves actually evolve some of the larger quantity o^ car-
bonic acid which had been absorbed during the previous daylight.
It is well known that any plant, or single branch of a plant,
secluded from light, does not acquire the usual green colour, but
remains white. In this state, the white leaves and stems exert
very little power, if any, in absorbing carbon. If the whole of
any plant is kept in the dark during its growing state, it must
soon die, for want of this essential source of sustenance.

1. Calcareous earth causes plants to draw more carbon from the
atmosphere.

The vigorous growth of plants, and the intensity or depth of
their green colour, always go together and in proportion to each

CALX INCREASING THE SUPPLY OP CARBON. 249

other. We must correctly infer that the deeper the green colour,
from whatever cause it may proceed in part (as rich manuring,
bright sunlight, or moist season), the greater must be the absorp-
tion of carbon by the leaves of the plant. Therefore, if in any
manner tlje intensity of the green colour of plants is increased, it
is equivalent to giving them the power of absorbing and assimilat-
ing more carbon, and with that (as before stated), the power of
taking up and assimilating the required proportional quantities of
oxygen and hydrogen.

r Now one of the earliest and most manifest effects produced by
adding calcareous earth to a soil before extremely needing that ma-
nure, is to give a deeper green colour to the plants. This effect is
so remarkable on young corn, growing on soil previously acid and
recently marled, that before the plants are four inches high, the
outlines of the spot made calcareous may be distinctly seen and
easily traced by any observer, merely by the strong contrast be-
tween the deep green colour of the plants on one side, and the
pale,'yellowish, and sickly green of the other ; and this before there
■is any obvious difference of size of the plants. And this difference
of colour remains so strongly impressed, that a strip of corn thus
treated, when of more advanced growth, may be distinguished at
the distance of half a mile, if exposed to view so far.

This early and marked effect of calcareous manures, of giving a
deep green colour to plants, I had formerly ascribed solely to the
neutralizing of the noxious acid of the soil. And this is doubtless
the cause in part. But more extended observations, and the abid-
ing effects of this kind, induced me to believe that a direct, as
well as the supposed indirect action was produced. But from
whatever cause it proceeds, it is unquestionable that the increase
of green colour is accompanied by proportionate increase of sup-
plies of atmospheric food to the plants, and proportionate increaseii^
products of the crops for the food of animals, and for food (or
manure) for the soil.

One other well-known agricultural fact will be cited in support
of this position. When gypsum (sulphate of lime) is applied to
clover, on a neutral soil (where there is no injurious excess of acid
to affect the crop, or to be removed by lime), and the gypsum acts
well, one of the earliest and most striking evidences of its benefi-
cial action is seen in the deeper green colour of the clover dressed,
compared to any omitted portions. This effort, however produced
(as said before), is equivalent and proportioned to an increased ab-
sorption of carbon from the atmosphere ; and, as in the previous
case, must be ascribed to the increased power of absorption given
to the clover by the lime which is the base of the gypsum.

It may perhaps be questioned that such great effect can be pro-
duced by the operation of so small a quantity of lime as is con-

250 CALX INCREASING THE SUPPLY OF CARBON.

tained in a busliel of gypsum, tlae ordinary dressing for an acrei
But gypsum is easily soluble in enough pure water, and would
find enough in the earth furnished by rain for its speedy solution ;
whereas carbonate of lime is insoluble in water, unless with the
addition of carbonic acid. Therefore it may follow, that Qven from
a bushel of the soluble gypsum, the crop may draw up lime more
readily and abundantly for the time, than from 100 bushels, or
more, of insoluble carbonate of lime. Boussingault ascribes the
great effect of gypsum to its easy solubility in water, and its thus
readily furnishing dissolved lime to the roots and to the body of .
the plant. Though this is not at all a satisfactory cause for all the
wonderful operation of gypsum on clover (and still less to explain
its very frequent want of effect), there can be no doubt of the
authority for the fact that the gypsum (or its lime) may be easily
so received into the sap of the body of the clover. And, as analysis
has shown that 1000 lbs. of dry clover hay contains 27 lbs. of
lime (Sprengel, quoted by Johnston, p. 220), and 100 lbs. of sul-
phate of lime freed from water contains 41.5 lbs. of lime, if fol-
lows that this quantity would suJEce for the healthful constitution
of as much clover as would be converted to more than 1500 lbs.
of dry hay.

The chemical facts which have been cited are well established,
and the agricultural facts have been observed by very many prac-
tical cultivators ; and both would seem sufficient to establish the
position that lime gives to plants greatly increased power for ab-
sorbing carbon from the air. But, in addition to these, some very
interesting and apparently accurate experiments have furnished
more direct and certain proof of the results above mentioned.
These will now be reported.

When nearly all the sheets of the preceding edition of this
essay (1842) had been printed, embracing the whole except parfc
of the Appendix, I first heard of the discovery having been made
by Dr. Wm. L. Wight, of Goochland, of the important property of
calcareous earth now under consideration. Forthwith I sought
and obtained from him information of his experiments and deduc-
tions ; and with his permission, a concise report of their substance,
together with such introductory and explanatory remarks as I
deemed required, was published among the papers of the Appendix
which then remained to be printed.

Soon after my publication as above stated, Pr. Wight placed his
discovery before the public more at length in his ^' Observations
on Vegetable and Animal Physiology,'' printed in 1843; from
which publication will be here copied all that applies to this subject.

After referring to the previous edition of the " Essay on Calcare-
ous Manures" especially, and also to other confirmatory publications,
tending to establish both the fertilizing and health-preserving

CALX INCREASING THE SUPPLY OF CARBON. 251

actions of calcareous earth in soils, Dr. Wight proceeded to say
that in his consideration of the subject "it became a question of
deep interest to determine what was the peculiar influence of lime
in the process of vegetation ; and for this purpose the following
experiments were instituted. Seeds of wheat, resting upon moist-
ened cotton, were first placed in glasses of water, and thus allowed
to germinate. When two or more plants had put forth five roots,
which is their complement, or an equal number, taking especial
care that those experimented with should have an equal number
of roots, this being the test of their being equally healthy, they
were immediately transferred, half of them to vessels of pure rain-
water, the other half to vessels of rain-water in which a small portion
of the hydrate of lime [or slaked quick lime] had been dissolved.

"As soon as the first leaf had attained sufficient length, they
were introduced under separate receivers, and supplied with car-
bonic acid. It was soon apparent, however, that the plants growing
in the pure rain-water threw ofi" more oxygen than the others,
though the difi'erence was slight. The experiment was repeated
with the other leaves, as they were successively unfolded, but with
no better success.

" The carbonate of lime, or lime in the state it is found as a
natural production, was now substituted for the hydrate. Select-
ing the thin pellicle which collects upon lime-water, and reducing
it to a fine powder, as much was previously dissolved in the rain-
water in which half of the plants were to grow as could be, by
brisk agitation for a few minutes in a closed bottle. The plants to
be experimented with being always transferred from the glasses as
soon as it was perceived that they had an equal number of roots.
Previous to the period at which plants become dependent upon ex-
terior influences, the efi'ect of the carbonate of lime was rather to
retard than to quicken the decomposing process ; but generally, by
the time the second leaf had fully unfolded itself, and always in
the case of the third, the greater resistance oflered to the touch,
and the deeper and more polished tint of green, inspired anticipa-
tions of a successful result. When introduced under the receiver,
and supplied with carbonic acid, these anticipations were more than
fully realized — the plants growing in rain-water in which carbo-
nate of lime had been previously dissolved, giving off two, three,
and sometimes four volumes of oxygen to one disengaged by those
growing in pure rain-water; and for every volume of oxygen
emitted, an equal quantity of carbonic acid disappeared from the
jar containing it. These experiments were frequently and care-
fully repeated with the other plants cultivated in this latitude,
until it seemed to be fully ascertained that the influence of the
carbonate of lime in the process of vegetable nutrition consists in
increasing the action of plants upon the light — in so modifying

252 CALX INCRBASINa THE SUPPLY OF CARBON.

their constitution as to dispose tliem to reflect, under the ordinary
defects of climate and season, their natural green ; and, by con-
necting this power with the other and well-known events in the
scries, viz. the more active decomposition of carbonic acid, where-
by more carbon, the basis of vegetable matter, is assimilated, and
more oxygen returned to the atmosphere, we obtain, as is conceived,
a consistent explanation of the action of lime, both in the pro-
motion of the fertility of the soil, and in the restoration of the
air to its purity.^' Observations, ko,., pp. 9, 10.

These interesting experiments have still later been repeated by
Dr. Wight, and always with the like results. There can be no ques-
tion of the care and accuracy with which they have been conducted ;
and very little ground to object to the conclusiveness of the posi-
tion which the results demand — that is, that the effect of carbonate
of lime, acting through the roots of the plants, enabled them to
absorb and to assimilate at least more than a doubled quantity' of
carbon, and consequently to disengage more than a doubled quan-
tity of oxygen gas, formed by the decomposition of the carbonic acid
taken in by the plants. The only apparent defect in the process
is one which is unavoidable. This is, that the wheat (or other)
plants were made to grow with their roots in water, a situation
contrary to their nature and wants; instead of in dry soil, con-
formable to both. But in naming this unavoidable defect, I do
not mean to convey that it can invalidate the results of the experi-
ments, or even reduce their measure in any very important extent.

But there is one deduction which Dr. "Wight seems to have
made, to which it is scarcely necessary for me to announce my
dissent. While I fully admit that he has first indicated, and at
least gone far to establish by his experiments, one of the very im-
portant properties and powers of calcareous earth, as a fertilizing
manure (and also as a sanitary agent), still I do not agree that this
is its sole or even the most important mode of operating, for
either end.

The bearing of Dr. Wight's experiments on the effect of calca-
rtrous manures in preserving health, will be referred to when that
subject shall come under consideration. All reference to this
branch of the subject in this chapter was incidental and in advance
of the designed and more appropriate place.

The power given by calcareous earth to plants to draw carbonic
acid much more copiously from the atmosphere, which Dr. Wight
so admirably deduced from actual experiments, might previously
have been inferred from the observations of alleged facts made by
practical cultivators. But the statement, hidden in the German
of the agricultural chemist Sprengel, probably first was disclosed
in this country in the recently published "Lectures'' of Johnston,
whose words I will quote. This author, referring to Sprengel,
Bays : " He states that it has very frequently been observed iu

GYPSUM INCREASING THE SUPPLY OP CARBON. 253

Holstein, that if, on an extent of level ground sown with corn,
some fields be marled and others left nnmarled, the corn on the latter
portions will grow less luxuriant!;!/, and will i/ield a poorer crop
than if the ivhole had been unmarled. Hence, he adds, if the
occupier of the unmarled field would not have a succession of poor
crops, he must marl his land also.

" Can it really be,'' continues Johnston, ^' that Nature thus re-
wards the diligent and the improver? Do the plants which grow
on a soil in higher condition take from the air more than their due
share of the carbonic acid or other vegetable food it may contain,
and leave to the tenants of the poorer soil a less proportion than
they might otherwise draw from it ?" (p. 101.) Like most other
readers, probably, I cannot venture to answer these questions
affirmatively. But if indeed calcareous earth in soil gives to plants
the power to seize upon and assimilate a much larger amount of
carbonic acid, it may well follow that other adjacent plants, not so
endowed, may in the contest fail to obtain their previously due
share of the always very small proportion of carbonic acid gas in
the atmosphere.

In connexion with these interesting statements, I will add an-
other, which is fully believed by many persons, and which I have
also heard asserted by one of the best practical farmers of Virginia,
and who is also an intelligent and judicious observer. The opinion
referred to is, that if a narrow strip of a clover-field be omitted, for
experiment and observation, when all the adjoining ground is
dressed with gypsum (sulphate of lime), and the manure acts well,
that the omitted strip will produce worse clover than it would have
done if no gypsum was near. The farmers who maintain this pro-
position, do so simply upon having observed (as they conceive)
such facts. They had no theoretical views to support by such a fact,
and indeed they did not pretend to ofi'er a supposed cause for such
an efi'ect. For my own part, I have had no opportunity of observ-
ing any such facts, and will neither affirm nor deny such to have
been accurately observed by others. But such results seemed so
unsupported by reason, that at first I deemed the observations
mistaken, and the statements not worth any consideration. But by
applying the obvious deductions from Dr. \Yight's experiments,
these before (supposed) irrational and incredible results may appear
well sustained, both in regard to their accuracy and their causation.

2. Lime in soil increases the effect of azotized mamires, andj
through leguminous plants^ draws azote also from the atmo-
sphere.

The quantity of carbon in plants, or in diffisrent products of
plants, amounts, in some subjects, to more than one-half of the
whole weight of the dry plant or product 3 and in all other cases it
22

254 AZOTE IN PLANTS.

falls not much bolow tliat proportion. According to Professor
Liebig, the whole of the carbon in plants is derived, through their
leaves, from the atmosphere ; and Boussingault, whose authority I
respect much more highly, says : " From all we have seen up to
this time, we feel authorized to conclude that the greater proportion,
if not the whole, of the carbon which enters into the composition
of vegetables, is derived from the atmosphere.'" (p. 42.) All other
chemical authorities concur in maintaining that at least much the
larger part of the carbon received by and fixed in plants, is taken
from the atmosphere through the leaves. How very greht, then,
must be the proportion of vegetable nutriment and support, and of
materials for growth and increase, derived exclusively from the air !
For it is not only that nearly half their quantity is thus obtained
in their carbon alone, and they also take up from water, whether
in the air or in the soil, nearly as much as of carbon, in hydrogen
and oxygen; which, though always present in enormous siiper-
abundance, cannot be thus used by plants, except in strict propor-
tion to the carbon assimilated. AH these quantities, then, which
the atmosphere supplies either exclusively, or may supply, as in
regard to water, probably amount always to full four-fifths of the
substance of all vegetable products; leaving but one-fifth, at most,
to be derived from the soil, or having any direct dependence on the
condition of fertility of the soil.

Further : of thi^ small proportion of vegetable growth and sub-
stance derived from and dependent on the contents of the soil —
say one-fifth, at most, and generally not more than one-tenth part
— a quantity which varies much in difi"erent plants, but on an
average making more than half of this proportion derived from the
soil alone, consists of inorganic elements ; while the remainder, of
about 1 to 4 per cent, only of the whole plant, is of azote, which
is either wholly or principally a part of the matter derived from
the contents of the soil. (See Table on p. 244.) Yet is this very
small supply of azote all-important to the support and product of
plants ; and its being duly supplied in organic manures, or other-
wise, is the great and essential operation of all improvement of
crops through the improvement of soils. In considering, then, the
value of azote, we must take care not to measure its importance by
its always small quantity in soils, manures, or plants, but by the
great and essential operation of this element, and which even in
this small quantity it produces. Azote is eminently the enriching
part of all putrescent manures, and of all vegetable products serv-
ing as food for animals. The most enriching of animal manures
abound most in azote ; and, above all, the excrements of carnivorous
animals, whose food is also rich in azote. Next in order ^stand the
excrements of animals fed on the most highly azotized 'vegetable
food. Vegetable matters, compared to animal, in general have but

AZOTE IN PLANTS.

255

little azote; and, as we all know, when used alone, make much
poorer manure. But even among diiFerent vegetables forming
ordinary farm products, there are great differences in their propor-
tions of azote, and also in their sources of supply of this rich
ingredient ; and according to such differences are the respective
values of crops for food, and more especially their powers as im-
provers or exhausters of the soils on which they grow. The in-
vestigation and attempt at elucidation of this last branch of the
subject is the object of the next following pages.

Boussingault reports (from the results of analyses by himself and
Pay en, in conjunction) the proportions of azote contained in nume-
rous vegetable and animal substances (at p. 297, Rural Economy)^
from which the following extracts of some ordinary manuring ma-
terials will serve as examples : —

Ordinary farm-yard manure, 100 parts, dry, contained of

azote

.

.

,

. 1.95

Richer manure, from an inn-yard -

.

2.08

Wheat-straw of Alsace [presumed from ordinary

soil]

0.30

Do., from environs of Paris [presumed much richer soil] .

0.53

Rye-straw of Alsace . . . .

0.20

Do., environs of Paris .

0.50

Oat-straw

0.36

Barley-straw

0.26

Wheat-chaff

0.94

Pea-straw [or vines, &c.]

1.95

Clover roots

1.77

Oilcake of flax-seed

6.00

Do. cotton-seed

4.52

Solid cow-dung

2.30

Solid horse-dung .

2.21

Guano

6.20

Dried muscular flesh

14.25

Woollen rags

20.26

While I do not deem the azotic as the only fertilizing parts of
putrescent manures, nor concur in all that Boussingault seems to
claim for their preponderance of operation, still it cannot be denied
that the azote of all organic manures constitutes their principal and
greatest fertilizing quality. Hence, we may learn, that if by any
means, and from new or additional sources, there can be given to
plants an additional supply of azote, of which the absolute quantity
would be so small as to seem scarcely worth consideration, yet that
there would be added relatively as much amount of manuring value
as a larger dressing of ordinary manure could supply. And a due
'consideration of these premises will serve to increase the estimate

256 SOURCES OP SUPPLY OP AZOTE.

of the importance of the sources of supplies of azote which will be
indicated.*

Azote is mostly derived by plants from the soil and through
their roots. This is made evident by the obvious effects of all
putrescent manures, and the superior effects of those known to be
richest in azote. But it seems from some delicate and careful ex-
periments of Boussingault's, that some particular plants, and, as
far as known, those belonging to the leguminous or pod-bearing
kind only, possess the power of also deriving azote from the atmo-
sphere. This power, if certain, would be enough to explain the
reason of the well known and peculiar value of leguminous plants
as manuring crops. *

This eminent chemist and practical agriculturist sowed known
quantities of the seeds of different kinds of plants in artificial soils,
composed of either burnt clay or silicious sand, which had been
deprived of all azotic and other alimentary manuring principles by
sufficient exposure to a high degree of heat. In other cases, young
plants were removed from natural soils to such artificial soil, after
being completely cleared of all adhering earth. The vessels con-
taining the soils and plants were protected from receiving dust, or
anything else from without, and the seeds and plants therein were
duly moistened with distilled water. The plants, in some cases,
stood until mature; in others, for shorter terms. Finally, the
several kinds were analyzed, as had been done of the like kinds of
seeds, or transplanted plants, from which they grew, and the differ-
ences of contents noted (omitting the ashes, or inorganic parts),
as shown in the following summary of the results : —

* Ordinary barn-yard manure, which has been heaped, partially fer-
mented, and is half rotted, is the kind which M. Boussingault used on his
farm and in his analyses. Such manure was considerably richer than ours,
made with fewer and worse-fed cattle, compared to the large proportion of
litter, and used without being heaped or fermented. His manure, also, in
a heap, would necessarily have less water. Yet he estimates the water alone
at from 75 to 80 per cent, of his manure. Of course, when dried, as stated
in the preceding table, 100 parts of such manure is equal to at least 400
parts in the heap ; and, therefore, these 400 parts in ordinary condition
contain only 1.95 parts of azote — or less than the half of one per cent,
serving to constitute the principal enriching value of the manure.

AZOTE SUPPLIED FROM THE AIR.

267

Weight (grains.)

1

1

1

-«5

1st. Clover seed sown

Plants at 3 months, from same

Gain by growth .

24.48 consisting of
63.38

12.44
32.141

1.466
4.183

8.815
24.155

1.759
2.408

38.90

+19.70

+2.717

+15.840

+0.649

2d. Peas sown ....
Plants (with seeds ripe) from
same

Gain by growth .

16.549 ....
68.560 ....

7.950
36.680

1.065
4.384

6.523
25.930

0.710
1.559

52.02

+28.73

+3..319

+19.11

+0.849

3d. Wheat seed sown

Plants from same, at 14 to 15
inches high

Gain by growth .

25.38 ....
45.65 ....
21.27

11.84
22.47

1.46
2.67

11.19
20.57

0.87
0.92

+10.63

+1.21

+9.38 '

+0.05

4th. Young clover plants .

Same after 63 days' growth

Gain by growth .

13.64 ....
34.96 ....

21.32

5.92
18.52

0.74
2.23

6.46
13.32

0.50
0.864

+12.60

+1.49

+6.86

+0.35

5th. Young oat plants

Same after 48 days' growth

Gain and loss in growth .

::::;;

12.967
23.157

1.636
2.979

8.770
21.180

0.910
0.818

+10.190

+1.343

+12.410

—0.062

The above table is an epitome of the results of the five experiments
which, with the full explanations, occupy about five pages of the
author's work. The analyses made of seeds and plants at the
earliest times, were, of course, of other samples, of like kind and
quantities of seeds to those sown, and, as nearly as could be, of the
plants, compared to those transplanted. The results show the
following facts : —

As the artificial soils were devoid of all organic or nutritive
matter, the gains made by the plants were derived entirely from
pure (distilled) water, and from the atmosphere. The increase in
azote, of course, could have been obtained from the atmosphere
only.

Besides the large gains made during growth, by all the plants,
of carbon, hydrogen, and oxygen, the clover of 1st experiment
increased its azote by more than half the quantity contained in the
seeds ; in the clover of 4th experiment, the azote of the young
plants was nearly doubled ; and in 2d experiment, the azote of the
peas sown was more than doubled in the crop.

In the growth of wheat, the gain of azote was scarcely appreci-
able (and, therefore, perhaps doubtful) ; and in the growth of oats,
there was an absolute loss of azote.

The results of these very interesting and apparently very accu-
rate experiments (as seen in the author's full details), exhibit, in
a striking manner, how largely all the kinds of plants possess them-
22*

258 BENEFIT OP CLOVER.

selves of and assimilate carbon, hydrogen, and oxygen, all drawn
from^vater and the air only; and also, that in addition to these ele-
ments, the leguminous plants, and these only, drew azote from the air,
assimilated or fixed it in their bodies, and thus could give it to the
soil as manure. When other plants contain azote, and give it to
the soil as manure, they had derived the whole supply previously
from the soil, and therefore there was no gain in regard to that
richest element. But the leguminous plants, deriving part of their
azote from the atmosphere, give so much to the soil, if used as
manure, more than the soil had before furnished. This peculiar
power of leguminous plants is an important cause of their well-
known peculiar value as manuring crops.

It has long been a received and unquestioned opinion among in-
telligent farmers, that the growth of clover, and other leguminous
crops, drew away from the soil less of the fertilizing principles, and
returned to it more, than any others. This opinion prevailed in
districts where most of the product of clover was usually removed
from the fields, as well as in other places where the clover was
mostly left on the ground, to be ploughed under as manure. In
Lower Virginia, wherever improvements by calcareous manures and
by clover have correctly gone together, and however the rotations
of crops may difl'er in other respects, there is one part of the courses
of crops generally alike, viz., the succession of — 1st, Indian corn ;
2d, wheat ; 3d, clover ; and 4th, wheat. On some farms (of best
soil, which only can bear such severe cropping), this is the whole
course constituting a four-shift rotation. On others, and more
generally, a fifth year is added, of rest, or at most of pasturage
only, and interposed between the fourth crop, wheat on clover, and
the subsequent recurrence of the first crop in the series, Indian
corn. In either case, it is generally believed that the product of
the second crop of wheat, sown upon clover turned under as manure,
is usually about double that of the first crop of wheat following
corn, though the immediately preceding corn crop had received all
the prepared putrescent manure given. This great difference of
production, however, is not altogether due to the clover manure
for the second, or " fallow'' crop of wheat, but partly to the cir-
cumstance of the first crop of wheat having followed another grain
crop, which is a vile succession, and must always lessen the second
or immediately succeeding crop more than in proportion to the then
actual productive powers of the land. In my own practice, as in
general of others, there have been no separate measurements of
these two nearest crops of wheat, or any parts thereof, from the
same land. But the same estimate of difference has iDcen made
upon merely general observation, viz., that the wheat after clover
was usually double as much as the previous wheat after corn on
the same field. My own putrescent manure, from stable and stock-

3(1

({

4th

u

5th

a

BENEFIT OP CLOVER TO WHEAT SUCCEEDINa. 259

pens, has been given exclusively as top-dressing to the clover, which
is so much the more in favour of the succeeding wheat.

The scientific and practical farmer as well as able ~ chemist,
Boussingault, has with great care ascertained the usual or average
quantities, and also the chemical contents, of the clover and all the
other crops of his rotation, so as to make certain the results which
with other persons would rest merely on supposition, or loose esti-
mates. On his farm, Bechelbronn in Alsace, he says — " For a
long time a five years' rotation has there been adopted in the fol-
lowing order : —

1st year. Potatoes, or beet-root, manured.

2d " Wheat, sown the autumn of the first year; clover in
the spring.
Clover, two crops [mown] ; the third ploughed in.
Wheat on the clover break; turnips after the wheat.
Oats.

It should be observed of this rotation that the first crop of wheat
was preceded by potatoes, a forerunner very favourable to the pro-
duct of the succeeding wheat; and still more so, as the potato
crop had all the manure of the farm. This crop of wheat, to the
acre, averaged 20 bushels and 31 lbs. of grain; and of both straw
and grain 4029 lbs. The clover following the next year yielded
2 crops of hay, making 4675 lbs. dry (or in state of hay), and a
third crop, ploughed in for manure. It is the usage in Alsace to
mow clover very young, when it is just beginning to get in blossom ;
hence the two mowings must have been removed so early, as to
allow the third growth to be as heavy as each of the two first.
Counting it then as one-third of the whole, the year's product of
clover, if all had been made into hay, would have weighed (4675-}-
2337=) 7012 lbs. ; of which one-third only was left on the land
as manure. After all this abstraction from the land, and also the
prepared manure having been applied to the first crop of the rota-
tion, the wheat following the clover yielded the average of 25 bush.
21 lbs. of grain, and straw and grain together 4979 lbs.

This rotation is general in Alsace ; and speaking of general re-
sults, M. Boussingault says — " The remarkable efi"ect of clover [as
a manure crop] has not failed to arrest the attention of the most
unobserving. The wheat crop which comes after our drill crop in
Alsace, beets or potatoes, averages from 18 to 20 bushels per acre ;
but the wheat succeeding clover averages from 23 to 24 bushels.^'
(p. 360.)

There is another important subject for consideration and com-
parison of clover and other crops (not leguminous), in their relative
quantities of roots, stubble, or other residues, or off"ul parts, left on
the land. In the same year (1839), when the season was not pro-
pitious to either crop, the residues were taken by M. Boussingault

2 GO CAUSE OP MANURING VALUE OP CLOVER.

from equal spaces, and after being perfectly cleared of tlie adhe-
ring earth, were dried, weighed, and also portions of each analyzed.
Of the two crops of wheat of that year, averaged, he found the
whole residue of stubble and roots to be per acre :

(from grain, weighing, lbs. 1075) lbs. 644
Residue of clover

stubble and roots (from hay, lbs. 2292) " 1833

Eesidue of oat stubble and roots (from grain, lbs. 1862) " 836

The residues of wheat and oats each contained per acre 2 lbs. of
azote only; while the residue of the clover contained 26 lbs. Of
course the superiority of the latter in quantity, great as it was over
the other residues, was still greater in richness, or quality for
manuring.

While all persons have concurred in asserting the meliorating
effects of clover and other leguminous crops, there has been as
general an erroneous agreement as to the cause of this quality. It
has been assumed by our scientific instructors, and their doctrine
was received without question, that plants with broad leaves ab-
sorbed more carbon from the air, and hence the superiority in this
respect of leguminous plants over all of the narrow-leaved tribes.
Never was there an opinion more generally admitted on a weaker
foundation, or more easy to overthrow. Several cultivated crops,
as tobacco, palma-christi, cabbage, turnip, pumpkin, and other like
vines, have much broader leaves than any of the legumes ; but
neither of these has ever been deemed to have any peculiar power
for manuring by its growth and decay on the land. Nearly all
forest trees also have very broad leaves, and they exhibit no su-
periority of manuring qualities on that account, whether compared
with narrow-leaved trees, or with leguminous crops. But is enough
to refer to the numerous analyses of plants reported by chemists,
all of which, like those in the table copied on a preceding page
(244) go to show that clover, beans, peas, vetches, &c., have in
general no larger proportions of carbon than other and even the
most exhausting plants. Indeed, of this element there is a close ap-
proximation to equal proportions in all plants whose constituent
parts have been reported. The proportion usually varies between
45 and 50 per cent, of the whole dry weight of the plant. From all
these facts, it may be inferred as being nearly a correct rule, that in
general the plants or crops which yield the greatest quantity of total
product to the acre, in dry weight, will have taken up (from all
sources, and of course mostly from the atmosphere) the largest
amount of carbon; and therefore will return more to the land if
left to act as manure. We must then look to other powers than
that of absorbing carbon for the cause of the superiority of clover
as manure — which, as Boussingault says, is out of all proportion

VALUE OP THE SOUTHERN PEA. 261

to the quantity of the crop given to the soil. That cause, I presume,
will be found partly in the greater product and quantity of residue
to the acre than is left by most other crops ; but still more because
of the greater quantity of azote contained in the residue of roots
and stubble, as well as of the crops consumed as forage, or left to
be ploughed under, and in both cases, though in different ways,
serving as manure to the land.

Of grain crops, or any others which take all their contents of
azote from the soil, and, if sold or removed from the farm, those
which have taken up and removed the most azote from the land,
must be the most exhausting of its fertilizing principles. And such
would be the leguminous crops, far beyond all others, if they came
under the conditions named, as they contain much the largest quan-
tities of azote. As they are known by observation to be among the
least exhausting, even when removed from the farm, that alone
would strongly indicate, what Boussingault's experiments have
proved, that these crops take a portion, and probably the larger
portion, of their azote from the atmosphere. - Of course, when re-
turned to the earth as manure, the azote so drawn from the air is
so much of supply of the richest principle, in addition to all others
contained, in common with other vegetable substances. We can
supply barn-yard and other animalized and azotized manures to our
fiirms only in limited and insufficient quantities. But by ploughing
in leguminous manuring crops, azote may be furnished to much
greater extent.

Field peas, such as are raised in England, and in our Northern
States, are varieties of and very like to the kinds we know here only
as garden vegetables. These field peas contain even more azote
than clover does. Lucerne is also superior to clover in that respect,
and European field beans not inferior. All these pl^ts are un-
suited to our climate, or unprofitable for culture on extensive
spaces.

But we have a leguminous plant, in numerous varieties, native
to our country, and little known except in Virginia and the more
Southern States, which, as a green manure, and meliorating crop,
is scarcely inferior to clover — and for some qualities, and always in
more southern regions, is preferable to clover. This is our southern,
or "corn-field pea,'' as commonly called, from being most generally
raised as a secondary crop among corn. In truth it is not a pea,
but a hean."^ Of this plant, I know of no chemical analysis. But

* Miller's Gardener's Dictionary states a sufficiently plain distinction
between beans and peas, by describing the seeds of the former as *' kidney-
shaped," and the latter as "roundish." The only pea known to me as a
cultivated plant, other than our European garden peas, has very small and
"roundish" pale green seeds, in a black pod. Even this is more like the
vetch {vicia saiiva) or our bad weed the "partridge pea," as to seeds and

262 AZOTE SUPPLIED THROtGH PEA CROPS.

it may be safely inferred, from its being a legume, from its luxuri-
ance of growth, and also from all of the little careful observation
that has been yet directed to it, that our native southern pea or
bean is a fertilizer of great value, and whose value in this respect is
just beginning to be understood. My own experience of this plant,
in field culture, is but a few years old. But it has been so encourag-
ing in the results, that I have already extended this growth, so as to
make it occupy an entire field, and to make an important part of
my rotation. It is too soon yet to rely on such recent facts and
observations. But so far as tested by my experience, I have every
reason to value highly this as a manuring crop, and especially as a
preparatory crop for wheat.*

If this plant was not an annual, and requiring (when sown sepa-
rately as a fallow or manure crop) to have the land ploughed for
its seeding, it would be more valuable than clover. This defect is
however in one aspect an advantage ; as we can raise the crop in
three or four months from the seeding, to the state of full growth
fit for ploughing under, with more certainty of success, both in the
standing and producing, than with clover in sixteen months from
the sowing. Farther south, the growth and production of the bean
crop becomes better, in proportion as clover becomes more precari-
ous and generally unproductive.

In the preceding pages I have endeavoured to explain and to
establish these opinions :

1. That azote, the smallest but richest, and for its quantity by
far the most important element and ingredient of plants, is derived
by most plants exclusively from the soil ;

2. That plants of the leguminous tribe, and they alone, so far as
known, possess and exert the power also to draw azote directly from
the atmospt^re, assimilate and fix in their bodies this richest ma-
terial, and to give it as manure to the soil on which they grow, and
are left to decay;

3. That owing to this peculiar power, leguminous plants are the
most highly enriching to soil, as manure.

pods, than to any known pea. But unlike the vetch, it is not a vine, but
a shrub.

* The varieties of these beans are innumerable. The most common and
best known as an excellent table vegetable, is the "black-eyed pea," of
which the seed is white with a black spot around the eye or germ. This
name, made doubly incorrect, is extended in common parlance, and in lists
of prices-current, to all the varieties of this crop, and seeds of various
colours. All the white kinds are the least valuable for green manuring
crops, because producing least vine and leaf. The greatest " runners," or
producers of vines, and making the heaviest cover to the ground, are all late
peas, and either black, red, or pale buff colour. There are many varieties,
with differences of time and manner of growth, even of these colours ; and
the seeds of one colour not distinguishable from other kinds of like colour.

LIME AIDING LEGUMINOUS PLANTS. 263

And that the important benefits thus to be derived are available
only through the aid of lime in soil, is the important deduction
from the foregoing positions, as premises, which I now design to
maintain.

It is not necessary' to repeat the many statements, in the forego-
ing portion of this essay, of the peculiar and all-important aid and
support which calcareous matter in soils furnishes for the growth
and luxuriance of leguminous plants especially. In some small
proportion, lime in soil is essential to the life of all plants, and to
even the poorest product from all cultivated crops. In larger,
though it may still be but very small proportion, it further and
greatly improves the growth and production of all cultivated crops,
and all except acid plants. And lime in greater quantity still, in
amount serving to constitute truly calcareous soil, is especially
promotive of the vigour and luxuriance of growth of all leguminous
plants, and even essential to the existence of some of them. Saint-
foiu, a valuable forage plant of highly calcareous lands in Europe,
cannot live in any natural (non-calcareous) soil of our Atlantic
slope. Lucerne, for the same reason, rarely thrives here, and never
except in the best artificial soils. Red clover, the chief of manuring
and forage plants, and which now serves as one of the principal and
essential elements of our present improving agricultural system, in
connexion with the use of calcareous manures, had no existence
and could not exist in field culture in the tide-water region before
the fitting the soils for its support, by the use of marl and lime.

To the next most important legume and manuring plant, our
field pea or bean, lime in quantity is as much conducive to its greatest
production, as to clover; but it is not so essential for the existence,
and moderate productiveness, of this kind of bean.

3. Operation of calcareous earth to produce nitrates in soilj
and compost heaps.

In sundry marginal notes to the foregoing pages, the recent
words or opinions of Prof. Johnston have been quoted, to show
their concurrence with my own earlier stated positions. It is highly
gratifying to me that such confirmation, having such authority,
may be adduced to support nearly every deduction of mine that
bears strongly upon, or would either direct or divert practical ope-
rations. His lecture " on the use of lime as a manure,^' especially
ofi'ers a copious mass of information on this subject, both scientific
and practical, which is generally correct, and more instructive than
all that had been before published by preceding English chemists
and agriculturists. When so many points of agreement appear of
this scientific work with mine, which has so little pretension to
science, it is well that my priority of publication must secure me
from any possible charge of plagiarism. I am altogether unqualified

264 L13IE INDUCING TUE FORMING OF NITRATES.

to judge of many of the chemicai doctrines and facts presented by
Johnston; but infer that they are among the unquestioned results
of the latest and ablest chemical researches. As a matter of course,
the scientific author may be supposed to have no personal acquaint-
ance with practical farming. But his numerous agricultural facts,
though received from other persons, are not less the fruits of
practice and observation, and therefore are worthy of much respect,
even when not to be admitted as conclusive. Though knowing
nothing of this author, except from his book, and confessedly unfit
to decide on the correctness of many of its scientific positions,
still I accept this work as the latest and fullest embodiment and
digest of the now received doctrines of agriculturaLchemistry in
Europe, and of agriculture in England; and so esteeming the work,
it will be again referred to, as has been done before, whether for
support of my own positions, as in many previous citations — or to
derive new lights and information, as now, — or to oppose or refute,
as has been attempted in other cases.

This section will present additional effects and valuable opera-
tions of calcareous manures, for which subjects, either wholly or
in part, I am indebted to Johnston, and to whom the credit*"' due
will be particularly as well as thus generally awarded. The most
interesting and important of such new or additional positions, ia
the power of calcareous earth, in soil, or in compost heaps of
manure, to form nitrates from atmospheric supply of material.

The same two elements, oxygen and nitrogen, which when in-
termixed in gaseous form, and in certain uniform proportions, serve
to make atmospheric air, will, when chemically combined, consti-
tute nitric acid. Such combination is produced by electricity. '^ It
is known," says Boussingault, " that so often as a succession of
electrical sparks passes through moist air, there is formation and
combination of nitric acid and ammonia. Now nitrate of ammonia
is one of the constant ingredients in the rain of thunder-storms.''
(p. 494.) '' The currents of electricity which in nature traverse
the atmosphere must produce the same effect [of forming nitric
acid], and the passage of each flash of lightning through the air
must be attended by the formation of some portion of this acid."
(Johnston, p. 160.)

Ammonia, the volatile or aeriform alkali, is a cliomical compound
of nitrogen (azote), one of the two elements of avmospheric air,
and hydrogen, one of the two elements of water. IJence, of am-
monia, as of nitric acid, there are in the ordinal y moi^t air of the
atmosphere, the most abundant materials for both ihgst. compound <
products. There is wanting only the agency for their f-^rmation,
which is exercised by nature only (as by lightning), and that spa-
ringly, though incessantly, in some or other regions of the tmo-
ephere. Both ammonia and the nitrates (the certain and }ii>me-

CALCAREOUS COMPOSTS ARE NITRE-BEDS. 265

diatc products of nitric acid on the soil), are well known to be
highly fertilizing. The foregoing passages show (besides other
known sources) that the air supplies both, and that the surface
of the earth, everywhere, is sure to be more or less supplied from
the air, with ammonia and nitric acid. Nitrogen, which is ono
of the two constituent parts of both these fertilizing compounds, is
also the richest and the most important element (for the small pro-
portion required), in the nutriment of plants, and the most power-
ful promoter of their luxuriance and perfection of growtl^ It may
be inferred, that it is by furnishing their element nitrogen to
plants, that both ammonia and the nitrates are such important aids
to vegetable growth, and to the fertility of soils. Ammonia is
produced and evolved in large quantity by the putrefaction of all
animal substances. Also, "during the decay of vegetable sub-
stances in moist air, ammonia is formed at the expense of the hy-
drogen of the water and of the nitrogen of the air. In conse-
quence of, or in connexion with, such decay, nitric acid is also
largely produced in nature.''-— (Johnston, p. 161.)

" The most familiar, as well as the most instructive examples of
this formation of nitric acid, is in the artificial nitre-beds of France
and the north of Europe. These are formed of earth [calcareous
in part], stable manure, or other animal and vegetable matters, the
mixture laid in ridges, occasionally watered with liquid manure,
and turned over, to expose fresh portions to the air. After a time,
perhaps once a year, the whole is washed, when the water which
comes off is found to contain a variable quantity of the nitrates of
potash, soda, lime, and magnesia, which arc employed for the manu-
facture of saltpetre. In these nitre-beds, it has been observed that
the production of nitric acid either does not take place at all, or
only with extreme slowness, unless animal and vegetable matter be
present in considerable proportion. And yet the quantity of nitric
acid which is formed is much greater than could be produced by
the oxydation of the whole of the nitrogen contained in the organic

matters present in the mixture It appears, therefore,

that organic matters are, in our climate, necessary to cause the for-
mation of nitric acid to commence ; but that after it has begun, it
will proceed in the same heap for an indefinite period, and at the
expense apparently of the nitrogen of the air only.

" Compost heaps [of manure, formed of rich soil, animal manure,
and lime or calcareous earth] are in general only artificial nitre-
heds, often unskilfully prepared, and badly managed, producing,
however, a certain quantity of nitrates, to the presence of which,
their effecfon vegetation may not unfrequently be ascribed. . . .
The soils in the plains of India, and in other similar spots in the
tropical regions, may be regarded as natural nitre-heds, in which
the decay of organic matter being vastly more rapid than in our
23

266 LIME IN COMPOST HEAPS.

temperate regions, the production of nitric acid is rapid in propor-
tion/'— (Johnston, p. 161.)

Thus, and in other modes, by the presence and agency of calca-
reous earth, it may be supposed that nitrogen (or azote), which is
the essential element of all rich putrescent manures, is continually
produced from the atmosphere 3 and that the results, in nitrates,
are given to growing plants, by which they obtain and assimilate
the necessary nitrogen, which could not be otherwise obtained, ex-
cept from large supplies of rich animal manures.

If these views are sound, they lead to most- important conse-
quences, and suggest the existence of before unknown enriching
and fructifying agencies of lime, continually at work, in drawing
rich manure from the air, and giving the supplies to each successive
crop of growing plants, so long as the lime and organic matter re-
main together in the soil.

These views also serve to throw much light on some opinions
and facts in reference to the benefits of lime, which I formerly
brought before the public, because of their interest, but of which
the causes were then left in all their obscurity. One class of facts
were presented in the very light limings of La Sarthe, in France^
of about 11 bushels only to the acre (though repeated in every
round of four crops), and showing undoubted good effects. Thi&
was stated in Puvis' " Essay on Lime,''* which I translated and
published in the third volume of the " Farmers' Register." The
other facts referred to, doubtless were produced by that publication.
Mr. Peter Mellett, of Sumpter, S. C, pursued a similar course of
liming, and even with still lighter though more frequent dressings,
giving but 2 J bushels to the acre, annually, and yet with satisfac-
tory results, and manifest and progressively increasing improve-
ment of both land and crops.f The process in both cases was to
form compost heaps of alternate layers of earth, putrescent manures,
and lime in very small proportion. In both cases, the evidences of
the results seemed unquestionable. Yet to me, the reported effects
then seemed to exceed the operation of all the then known causes,
in enormous disproportion. But the difficulties of comprehension
will be removed by explanations suggested by the passages quoted
above. These compost heaps were in fact nitre-beds; and the lime
acted much less by its quantity, and directly, as manure, than by
inducing the formation of nitrates, and thereby furnishing supplies
of nitrogen to the crops. Another circumstance strengthens this
conjecture. Puvis states of this practice, which was extensively

^ '* Des diffei'cns moyens d'amender le sol," in the " Amiales d* Agriculture
Fran^aise," for 1835-6.

f These facts were more fully stated in my "Report of the Agricultural
Survey of South Carolina," made in 1843, under the order and appoint-
ment of the government of that State.

LIME IN COMPOST HEAPS. 267

in nse in Normandy, that the longer the compost heaps were kept
before being carried out as manure, and the more often they were
cut down, the parts mixed, and again heaped, the richer and more
efficient would be the manure. Now this seemed scarcely less
strange than the general result. For, after as many mixings and
turnings of the mass as would serve for thoroughly separating each
ingredient, and mingling the whole together, with enough of time
for the combining chemical action between the different elements,
there appeared no reason why the compound mass could gain more
in richness, and the putrescent parts would probably lose, by con-
tinued exposure and further decomposition. But even if such
were the case as to the original materials of the compost, yet doubt-
less the formation of nitrates continued, and their quantity was in-
creased with every new exposure of surface, and through the whole
course of time.

Under these impressions, I now deem much more valuable and
worthy of imitation the very light limings, in compost, of La
Sarthe ; and as especially suitable when a farm throughout has
once been well calxed, and it is yet too soon to repeat the applica-
tion in any considerable quantity. This plan, of very light lim-
ings, in compost, offers ample remuneration for using lime as ma-
nure in localities so distant from the source of supply, that the
carriage of enough for ordinary dressings might be more expensive
than profitable.*

V

§ III. Improving iJie health, and promoting tJie vigour and perfec-
tion of plants.

The beneficial effects of calxing are not to be measured by the
mere increase of the bulk or quantity of products, and still less in
comparison with crops on similar land not yet calxed, in seasons
when both lands, according to their different qualities, yield well.
The addition of calcareous earth, when before greatly deficient, serves
to so improve the fitness of the land for vegetable production, that

* It may be of use to some readers, who have no access to either of the
works above referred to, to state here concisely the mode of making this
compost in Normandy, and also in Belgium, as reported by Puvis. He
says: — "There is first made a bed of earth, mould, or turf [peat], of a
foot or thereabout in thickness. The lumps are chopped down, and then
is spread over a layer of unslaked lime, of a hectolitre [2| bushels] for
every 20 cubic feet of earth. Upon this lime is to be placed another layer
of earth [of like kind], equal in thickness to the first, then a second layer
of lime ; and then the heap is finished by a third layer of earth." As soon
as the lime is fully slaked, by the moisture of the earth, *' the heap is cut
down, and well mixed ; and this operation is repeated afterwards, before
using the manure, which is postponed as long as possible, because the
power of the effect on the soil is increased with the age of the compost,
and especially if it has been made with earth containing much vegetable
mould "

268 LIME CAUSING HEALTHY GROWTH.

all plants grown thereon will be more healthy, more able to resist
all causes of disease and disaster, to bear up unhurt under injuries
of season, insects, &c., which would have either destroyed, or
greatly injured the feebler and diseased growth of a soil deficient
in lime. Plants thus receive that endowment which in regard to
animals is called a good physical constitution. And the difference
between the possession of this good constitution and the want of it,
whether in animals or plants, in most times for comparison, would
be as the difference between perfect health and full ability on the
one side, and of disease or decay on the other.

In this aspect, the superiority of product from calxed land, how-
ever great it may be over the uncalxed, in any particular season
not disastrous to the growth of either, is of less account and value
than the ability of the former to maintain good products, under
circumstances of injury which would greatly reduce the production
of the latter.

In addition to this much greater certainty of calxed land pro-
ducing crops proportioned to its fertility, than of the un-calxed, in
proportion to its lesser rate there is the further advantage that the
growth of the former is in comparison more perfect and more valu-
able than would be indicated by mere quantities. The grain of
wheat is heavier to the measure, has a thinner skin, and yields
more flour, on calxed soils, or those naturally calcareous ; ^' while
this flour is said also to be richer in gluten,'^ and of course will
make more and better bread. — (Johnston, p. 891.) These benefits
are in addition to the greater quantity and also the greater cer-
tainty of production. Though the millers of this country have
been slow to learn these truths, still they are beginning to know
that the wheat produced on calxed lands is the most valuable.
Johnston says that liming ^' improves the quality of almost every
cultivated crop.'' — " All fodder [grass, &c.], whether natural or
artificial, is said to be sounder and more nourishing when grown
upon land to which lime has been abundantly applied.'' — '' Pota-
toes are made more mealy and palatable, especially on moist lands
needing draining. Turnips, peas, and beans are also improved for
food^ in addition to the increase of crops."

CHAPTER XXV.

THE USE OP CALCAREOUS EARTH RECOMMENDED TO PRESERVE
PUTRESCENT MANURES, AND TO PROMOTE CLEANLINESS AND
HEALTH.

The operation of calcareous earth in enriching barren soils has
been, in a former part of this essay, ascribed mainly to the chemi-
cal power possessed by that earth of combining with putrescent
matters, or with the products of their decomposition ; and in that
manner preserving them from waste, for the use of the soil, and
for the food of growing plants. That power was exemplified by
the details of an experiment (page 95), in which the carcass of an
animal was so acted on, and its enriching properties secured. That
trial of the putrefaction of animal matter in contact with calcare-
ous earth, was commenced with a view to results very different
from those which were obtained. Darwin says that nitrous acid
is produced in the process of fermentation, and he supposes the
nitrate of lime to be very serviceable to vegetation.* As the
nitrous acid is a gas, it must pass off into the air, under ordinary
circumstances, as fast as it is formed, and be entirely lost. But as
it is strongly attracted by lime, it was supposed that a cover of
calcareous earth would arrest it, and form a new combination,
which, if not precisely nitrate of lime, would at least be composed
of the same elements, though in different proportions. To ascertain
whether any such combination had taken place, when the manure
was used, a handful of the marl was taken, which had been in im-
mediate contact with the carcass, and thrown into a glass of hot
water. After remaining half an hour, the fluid was poured off,
filtered, and evaporated, and left a considerable proportion of a
white soluble salt (suj^posed eight or ten grains). I could not
ascertain its kind; but it was not deliquescent, and therefore
could not have been the nitrate of lime. The spot on which the
carcass lay was so strongly impregnated by this salt, that it re-
mained bare of vegetation for several years, and until the field was
ploughed for cultivation.

But whatever were the products of decomposition saved by this
experiment, the absence of all offensive effluvia throughout the
process sufficiently proved that little or nothing was lost, as every
atom must be, when flesh putrefies in the open air ; and I presume
that a cover of equal thickness of clay, or sand, or any mixture
of both, without calcareous earth, would have had very little effect

* Darwin's Pliytologia, pp. 210 and 224. Dublin edition.
23* ^ (269)

270 ANIMAL MATTER FIXED BY CALCAREOUS.

in arresting and retaining the aeriform products of putrefaction.
All the circumstances of this experiment, and particularly the
good effect exhibited by the manure when put to use, proved the
propriety of extending a similar practice. In the neighbourhood
of towns, or wherever else the carcasses of animals, or any other
animal substances subject to rapid and wasteful putrefaction, can
be obtained in great quantity, all their enriching powers might be
secured, by depositing them between layers of marl, or calcareous
earth in any other form. It is said that on the borders of the
Chowan, herrings are often used as manure, when purchasers can-
not take off the quantities supplied by the seines. A herring is
buried under each corn-hill, and fine crops are thus made as far as
this singular mode of manuring is extended. But whatever benefits
have been thus derived, the sense of smelling, as well as the known
chemical products of the process of animal putrefaction, make it
certain that nine-tenths of all this rich manure, when so applied,
must be wasted in the air. If those who fortunately possess this
supply of animal manure would cause the fermentation to take
place and be completely mixed with and enclosed by marl, in pits
of suitable size, they would increase prodigiously both the amount
and permanency of their acting animal manure, besides obtaining
the benefit of the calcareous earth mixed with it.*

But without regarding such uncommon or abundant sources for
supplying animal matter, every farmer may considerably increase
his stock of putrescent manure by using the preservative power of
marl ; and all the substances that might be so saved are not only
now lost to the land, but serve to contaminate the air while putre-
fying, and perhaps to engender disease. The last consideration is
of most importance to towns, though worthy of attention every-
where. Whoever will make the trial will be surprised to find how
much putrescent matter may be collected from the dwelling-house,
kitchen, and laundry of a family ; and which if accumulated
(without mixture with calcareous earth), would soon become so
offensive as to show the necessity of putting an end to the practice.
Yet it must be admitted that when all such matters are scattered
about (as is usual both in town and country), over an extended
surface, the same putrefaction must ensue, and the same noxious
effluvia be evolved, though not enough concentrated to be very
offensive, or even always perceptible. The same amount is in-

* I have since heard that this mode of manuring, Tbut with the garbage
of the herrings, is a general and very extensive practice on the borders of
Albemarle Sound. By the enormous seines there used, herrings are taken
in numbers that seem scarcely credible ; and all the fish are trimmed and
salted at the fisheries. This great and regular supply of garbage used as
manure, is of great value, even with all the usual waste in the air ; but
would be of ten-fold value if treated as recommended above. .

FILTH OF TOWNS. 271

haled — ^but in a very diluted state, and in small though incessantly
repeated doses. But if mild calcareous earth in any form (and
fossil shells or marl present much the cheapest) is used to cover
and mix with the putrescent matters so collected, they will be pre-
vented from discharging offensive effluvia, and preserved to enrich
the soil. A malignant and ever acting enemy will be converted to
a friend and benefactor.

The usual dispersion and waste of such putrescent and excre-
mentitious matters about a farm-house, though a considerable loss
to agriculture, may take place without being very offensive to the
senses, or manifestly injurious to health. But the case is widely
different in towns. There, unless great care is continually used to
remove or destroy filth of every kind, it soon becomes offensive, if
not pestilential. During the summer of 1832, when that most
horrible scourge of the human race, the Asiatic cholera, was deso-
lating some of the towns of the United States, and all were ex-
pected to be visited by its fatal ravages, great and unusual exertions
were everywhere used to remove and prevent the accumulation of
filth, which, if allowed to remain, it was supposed would invite the
approach, and aid the effects of the pestilence. The efforts made
for that purpose served to show what a vast amount of putrescent
matter existed in every town, and which was so rapidly reproduced,
that its complete riddance was impossible. Immense quantities of
the richest manures, or materials for them, were washed away into
the rivers — caustic lime was used to destroy them — and the chlo-
ride of lime to decompose the offensive products of their fermenta-
tion, when that process had already occurred. All this amount of
labour and expense was directed to the complete destruction of what
might have given fertility to many adjacent fields — and yet served
to cleanse the towns but imperfectly, and for a very short time.
Yet the object in view might have been better attained by the pre-
vious adoption of the proper means for preserving these putrescent
matters, than by destroying them. These means would be to mix
or cover all accumulations of such matters with rich marl (which
would be the better for the purpose if its shells were in small par-
ticles), and in such quantity as the effect would show to be suffi-
cient. But much the greater part of the filth of a town is not, and
cannot be accumulated ; and from being dispersed is the most diffi-
cult to remove, and is probably the most noxious in its usual course
of fermentation. This would be guarded against by covering
thickly with marl the floor of every cellar and stable, back-yard
and stable lot. Every other vacant space should be lightly covered.
The same course pursued on the gardens and other cultivated
grounds would be sufficiently compensated by their increased pro-
ducts that would be obtained. But independent of that considera-
tion, the manures there applied would be prevented from escaping

272 MARL FOR €LEANSING TOWPfS.

into the air ; and being wholly retained by the soil, much smaller
applications would serve. The level streets ought also to be sprin-
kled with marl, and as often as circumstances might require. The
various putrescent matters usually left in the streets of a town
alone serve to make the dirt scraped from them a valuable manure ;
for the principal part of the bulk of street dirt is composed merely
of the barren clay brought in upon the wheels of wagons from the
country roads. Such a cover of calcareous earth would be the
most effectual absorbent and preserver of putrescent matter, as well
as'' the cheapest mode of keeping a town always clean. There
would be less noxious or offensive effluvia than is generated in
spite of all the ordinary means of prevention ; and by scraping up
and removing the marl after it had combined with and secured
enough of putrescent matter, a compost would be obtained for the
use of the surrounding country, so rich and so abundant, that its
use would repay a large part, if not the whole of the expense
incurred in its production. Probably one covering of marl for
each year would serve for most yards, cellars, &c.; but if re-
quired oftener, it would only prove the necessity for the opera-
tion, and show the greater .value in the results. The compost that
might be obtained from spaces equal to 500 acres, in a populous
town, would durably enrich thrice as many acres of the adjacent
country; and after twenty years of such a course, the surrounding
farms might be capable of returning to the town a ten-fold in-
creased surplus product. After the qualities and value of the
manure so formed were properly appreciated, it would be used for
farms that would be out of the reach of all other calcareous manures.
Carts bringing country produce to market might with profit carry
back loads of this compost eight or ten miles. The annual supply
that the country might be furnished with would produce very dif-
ferent effects from the putrescent and fleeting manure now obtained
from the town stables. Of the little durable benefit heretofore
derived from such means, the appearance of the country offers
sufficient testimony. At three miles distance from some of the
principal towns in Virginia, more than half the cultivated land is
too poor to yield any farming profit. The surplus grain sent to
market is very inconsiderable — and the coarse hay from the wet
natural meadows can only be sold to tavern-keepers, or those who
feed horses belonging to other persons — and to whom that hay is
the most desirable that is least likely to be eaten.

But even if the waste and destruction of manure in towns were
counted as nothing, and the preservation of health by keeping the
air pure were the only object sought, still calcareous earth, as pre-
sented by rich marl, would serve the purpose far better than
quick-lime. It is true that the latter substance acts powerfully in
decomposiug putrescent animal matter, and destroys its texture

INCONVENIENCES OF LIME. . 273

and qualities so completely, that the operation is commonly and
expressively called "burning" the substances acted on. But to
use a sufficient quantity of quick-lime to meet and decompose all
putrescent animal matters in a town would be intolerably expen-
sive, and still more objectionable in other respects. If a cover of
dry quick-lime in powder was spread over all the surfaces requiring
it for this purpose, the town would be unfit to live in ; and the
nuisance would be scarcely less, when rain had changed the suffo-
cating dust to an adhesive mortar. Woollen clothing, carpets, and
even living flesh, would be continually sustaining injury from the
contact. No such objections would attend the use of mild calca-
reous earth; and this could be obtained probably for less than one-
third of the cost of quick-lime, supposing an equal quantity of
pure calcareous matter to be obtained in each case. At this time
the richest marl on James river may be obtained at merely the cost
of digging, and its carriage by water, which, if undertaken on a
large scale, could not exceed, and probably would not equal, two
cents the bushel,*

The putrescent animal matters that would be preserved and ren-
dered innoxious by the general marling of the site of a town, would
be mostly such are so dispersed and imperceptible that they would
otherwise be entirely lost. But all such as are usually saved in
part would be doubled in quantity and value, and deprived of their
offensive and noxious qualities, by being kept mixed with calcareous
earth. The importance of this plan being adopted with the pro-
ducts of privies, &c., is still greater in town than country. The
various matters so collected and combined should never be applied
to the soil alone, as the salt derived from the kitchen, and the pot-
ash and soap from the laundry, might be injurious in so concen-
trated a form. When the pit for receiving this compound is
emptied, the contents should be spread over other and weaker
manure before being applied to the field.

Towns might furnish many other kinds of rich manure, which
are now lost entirely. Some of these particularly require the aid
of calcareous earth to be secured from destruction by putrefaction,
and others, though not putrescent, are equally wasted. The blood
of slaughtered animals, and the waste and rejected articles of wool,
hair, feathers, skin, horn, and bones, all are manures of great rich-
ness. We not only give the flesh of dead animals to infect the
air, instead of using it to fertilize the land, but their bones, which
might be so easily saved, are as completely thrown away. Bones
are composed of phosphate of lime and gelatinous animal matter,

* Such was the case in 1883 when this part was first published; but
now a half cent the bushel is the usual price charged for the best marl, as
it lies in the river banks.

274 CALX BETTER THAN QUICK-LIME.

and, wlien crushed, form one of the richest and most convenient
manures in the world; They are shipped in quantities from the
continent of Europe, and latterly even from this country, to be sold
for manure in England. The fields of battle have been gleaned,
and their shallow graves emptied for this purpose : and the bones
of the ten thousand British heroes, who fell on the field of Water-
loo, are now performing the less glorious, but more useful purpose
of producing, as manure, bread for their brothers at home.

There prevails a vulgar but useful superstition, that there is
^'bad luck" in throwing into the fire anything, however small may
be its amount or value, that can serve for the food of any living
animal. It is a pity that the same belief does not extend to every
thing that as manure can serve to feed growing plants — and that
even the parings of nails and clippings of beards are not saved (as
in China) for this purpose. • However small each particular source
might be, the amount of all the manures that might be saved, and
which are now wasted, would add incalculably to the usual means
for fertilization. Human excrement, which is scarcely used at all
in this country, is stated to be even richer than that of birds ; and
if all the enriching matters were preserved that are derived not
only from the food, but from all the habits of man, there can be no
question but that a town of ten thousand inhabitants, from those
gources alone, might enrich more land than can .be done from as
many cattle.

The opinions here presented are principally founded on the the-
ory of the operation of calcareous manures, as maintained in the
foregoing part of this Essay (Chap. YIII.), but they are also sus-
tained to considerable extent by facts and experience. The most
undeniable practical proof of one of my positions is the power of
a cover of marl to prevent the escape of all oiFensive effluvia from
the most putrescent animal matters. Of this power I have long
made use, and know it to be more effectual than quick-lime, even
if the destructive action of the latter were not objectionable.
Quick-lime forms new combinations with putrescent substances,
and, in thus combining, throws off effluvia, which, though different
from the products of putrescent matter alone, are still disagreeable
and offensive. Mild lime on the contrary absorbs and preserves
everything — or at least prevents the escape of any offensive odouF
being perceived. Whether putrescent vegetable matter is acted on
in like manner by calcareous earth cannot be as well tested by our
senses, and therefore the proof is less satisfactory. But if it is
true that calcareous earth acts by combining putrescent matters
with the soil, and thus preventing their loss (as I have endeavoured
to prove in Chapter VIII.), it must follow that, to the extent of
such combination, the formation and escape of all volatile products
of putrefaction will also be prevented.

EFFECTS OF CALXING ON HEALTH. 275

But it will be considered that the most important inquiry remains
to be answered, to wit : Has the application of calcareous manures
been found in practice decidedly beneficial to the health of the
residents on the land ? I answer, that long experience, and the
collection and comparison of numerous facts derived from various
sources, will be required to remove all doubts from this question ;
and it would be presumptuous in any individual to offer as sufficient
proof, the experience of only ten or twelve years on any one farm.
But while admitting the insufficiency of such testimony, I assert
that, so far [to 1833], my experience decidedly supports my posi-
tion. My principal farm [Coggins], until within some four or five
years, was subject in a remarkable degree to the common mild
autumnal diseases of our low country. Whether it is owing to
marling, or other unknown causes, these bilious diseases have since
become comparatively very rare. Neither does my opinion in this
respect, nor the facts that have occurred on my farm, stand alone.
Many other persons are equally convinced of this change on other
land as well as on mine. But in most cases where I have made
inquiries as to such results, nothing decisive had then been ob-
served. The hope that other persons may be induced to observe
and report facts bearing on this important point, has in part caused
the first appearance of these crude and perhaps premature views.

Even if my opinions and reasonings should appear sound, I am
aware that the practical application is not to be looked for soon ;
and that the scheme of using marl in towns is more likely to be
met by ridicule, than to receive a serious and attentive examina-
tion. Notwithstanding this anticipation, and however hopeless of
making converts, either of individuals or of corporate bodies, I will
offer a few concluding remarks on the most obvious objections to,
and benefits of the plan. The objections will all be resolved into
one — namely, the expense to be encountered. The expense certainly
would be considerable ; but it would be amply compensated by the
gains and benefits. In the first place, the general use of marl as
proposed, for towns, would serve to insure cleanliness, and purity
of the air, more than all the labours of their boards of health and
their scavengers, even when acting under the dread of approaching
pestilence. Secondly, the putrescent manures produced in towns,
by being merely preserved from waste, would be increased ten-fold
in quantity and value. Thirdly, all existing nuisances and abomi-
nations of filth would be at an end; and the beautiful city of
Richmond (for example) would not give offence to our nostrils,
almost as often as it offers gratification to our eyes. Lastly, the
marl (or mild lime), after being used until saturated with putres-
cent matter, would retain all its first value as calcareous earth,
and be well worth purchasing and removing to the adjacent farms,
independent of the enriching manure with which it would be-

276 ErpECTS OF calxing on health.

loaded. If tliese advantages can indeed be obtained, tlicj would
be cheaply bought at any price necessary to be encountered for the
purpose.

The foregoing part of this chapter was first published in the
Farmers' Register (for July, 1833), as supplementary to the pre-
vious edition of this Essay. That publication drew some attention
from others to the subject, and served to elicit many important
facts, of which I had been before altogether ignorant, in support
of the operation of calcareous earth in arresting the effects of
mala^ria, and the usual autumnal diseases of the Southern States and
other similar regions. These facts, together with the result of my
own personal experience, extended through two more autumns (or
sickly seasons, as commonly called here and farther south), since
the first publication of these views, will now be submitted. Most
of the facts derived from other persons relate to one region, the
'^rotten lime-stone lands'' of southern Alabama; but that region is
extensive, is of remarkable and well known character and pecu-
liarities, and the evidence comes from various sources, and is full,
and consistent in purport. The facts will be here presented in an
abridged form. The several more full communications, from which
they are drawn, may be referred to in the Farmers' Eegister, vol.
I., pp. 152, 214, and 277.

The first fact brought out was that, in the town of Mobile, near
' the Gulf of Mexico, the streets actually had been paved or covered
with shells — thus presenting precisely such a case as I recom-
mended, though not with any view to promoting cleanliness or
health. The shells had been used merely as a substitute for stones,
which could not be so cheaply obtained. Nor had the greatly im-
proved hejilthiness of Mobile, since the streets were so covered
(of which there is the most ample and undoubted testimony), been
attributed to that cause, until the publication of the foregoing
v^ opinions served to connect them as cause and effect. This can
scarcely be doubted by those who will admit the theory of the
action of calcareous earth ; and the remarkable change from un-
healthiness in Mobile, to comparative healthiness, is a very strong
exemplification of the truth of the theory. But it is not strange,
when so many other causes might (and probably did) operate to
arrest disease, that none should have considered the chemical
operation of the shelly pavement as one of them, and still less as
the one by far the most important. The paving of streets (with
any material), draining and filling up wet places, substituting for
rotting wooden buildings new ones of brick and stone — and espe-
cially the operation of destructive and extensive fires — all, we
know, operate (and particularly the last) to improve the healthi-
ness of towns ; and all these operated at Mobile, as well as shell-
ing the streets. Neither was the shelling so ordered as to produce

EFFECTS OF BURNINGS IN TOWNS. 277

its best effect for healtli. The streets, alleys, and many yards and
small vacant lots were covered, and so far the formation and evolv-
ing of pestilential effluvia were lessened. But as this was not the
object in view, and indeed the chemical action of shells was not
thought of, the process was incomplete, and must necessarily have
been less effectual than it might have been made. The shelling
ought to have been extended to every open spot where filth could
accumulate— to every back -yard, in every cellar, and made the '
material of the floor of every stable, and every other building of
which the floor would otherwise be of common earth. In addition,
after a sufiicient lapse of time to saturate with putrescent matters
the upper part of the calcareous layer, and thus to make it a very
rich compound, there should have been a partial or total removal
of the mass, and a new coating of shells laid down. The value of
the old material, as manure, would probably go far towards paying
for this renewal. If it is not so renewed, the calcareous matter
cannot combine with more than a certain amount of putrescent
matters ; and, after being so saturated, can have no further effect
in saving such matters for use, or preventing them from having
their usual evil (jourse.

The burning of towns is well known to be a cause of the healthi- -
ness of the places being greatly improved, and that such effect
continues after as many buildings, or more, have replaced those
destroyed by fire. Indeed this improvement is considered so per-
manent, as well as considerable, that the most sweeping and de-
structive conflagrations of some of our southern towns have been
afterwards acknowledged to have proved a gain and a blessing.
The principal and immediate mode of operation of this universally
acknowledged cause is usually supposed to be the total destruction,
by the fire, of all filth and putrescent matters ; and in a less de-
gree, and more gradually, by afterwards substituting brick and
stone for wooden buildings, which are always in a more or less de-
cayed state. But though these reasons have served heretofore to
satisfy all, as to the beneficial consequences of fires, surely they
are altogether inadequate as causes for such great and durable
effects. The mere destruction of all putrescent matters in a town,
at any one time, would certainly leave a clear atmosphere, and give
strong assurance of health being improved for a short time after-
wards. But these matters would be replaced probably in the course
of a few months, by the residence of as many inhabitants, and the
continuance of the same general habits ; and most certainly this
cause would lose all its operation by the time the town was rebuilt.
But there is one operation produced by the burning of a town,
which is far more powerful — which in fact is indirectly the very
practice which has been advocated-^ — and the effect of which, if
given its due weight, furnishes proof of the theory set forth, by
24

278 HEALTH ON THE CALCAREOUS PRAIRIES.

the experience of every unhealthy town which has suffered much
from fire. If a fair estimate is made of the immense quantity of
mild calcareous earth which is contained in the plastering and
brick-work of even the wooden dwelling-houses of a town, and still
more of those built of masonry, it must be admitted that all that
material being separated, broken down (soon or late), and spread, by
the burning of the houses and pulling down their ruins, is enough
to give a very heavy cover of calcareous earth to the whole space
of land burnt, over. It is to this operation, in a far greater degree
than to all others, that I attribute the beneficial effects to health
of the burning of towns.

I proceed to the facts derived from the extensive body of prairie
lands in Alabama which rest on a substratum of soft lime-stone, or
rich indurated clay marl. It was from these remarkable soils that
the specimens were obtained which were described at pp. 66, 67.
Some of these, indeed all that have been examined by chemical
tests, of the high and dry prairie lands, contain calcareous earth
in larger proportions than any soils of considerable extent in the
United States that I have seen or tested. The specimens not con-
taining free calcareous earth are of the class of neutral soils ; and
the calcareous earth, which doubtless they formerly contained, and
from which they derived their peculiar and valuable qualities, may
be supposed only to be concealed by the accumulation of vegetable
matter, according to the general views submitted in Chapter VII.

The more full descriptions of the soils of this remarkable and
extensive region before referred to render it unnecessary to enlarge
much here. It will be sufficient to sum up concisely the facts there
exhibited, and which agree with various other private accounts
which have been received from undoubted sources of information.
The deductions from these facts, and their accordance with the
theory of the operation of calcareous matter, are matters of rea-
soning, and, as such, are submitted to the consideration and judg-
ment of readers.

The soil of these prairie lands is very rich, except the spots
where the soft lime-stone rises to the surface, and makes the calca-
reous ingredient excessive. In the specimen formerly mentioned,
the pure calcareous matter formed 69 parts in the 100 of this
'' bald prairie" land. The soil generally has so little of sand, that
nothing but the calcareous matter which enters so largely into its
composition prevents it being so stiff and intractable, that its tillage
would be almost impracticable. Yet it is friable and light when dry,
and easy to till. But the superfluous rain-water cannot sink and
pass off, as in sandy or other pervious lands, but is held in this
close andiiighly absorbent soil, which throughout winter is thereby
made a deep mire, unfit to prepare for tillage, and scarcely practi-
cable to travel over. This water-holding quality of the soil; and

EFFECTS OF CALXING ON HEALTH. 279

.the nearness to the surface of the hard and impervious marly sub-
stratum, deprive the country of natural springs and running
streams ; and before the important discovery was made that pure
water might be obtained by boring from 300 to 700 feet through
the solid calcareous rock, the inhabitants used the stagnant rain-
water collected in pits, which was very far from being either pure
or palatable. Under all these circumstances, added to the rank
herbage of millions of acres annually dying and decomposing un-
der a southern sun, it might have been counted on,*as almost cer-
tain, that such a country would have proved very unhealth3^ Yet
the reverse is the fact, and in a remarkable degree. The healthi-
ness of this region is so connected with and limited by the calca-
reous substratum and soil, that it could not escape observation ;
and they have been considered as cause and effect by those who
had no theory to support, and who did not spend a thought upon
the mode in which was produced the important result they so
readily admitted. Their testimony therefore is in this respect the
more valuable, because it cannot be suspected of having any such
bias.

To the time when this last publication is made (1842) there has
been no reason to doubt the actual facts of autumnal diseases (the
effects of malaria) being greatly lessened by even the partial use
of marling; nor the inference that they would almost cease to
occur (if no mill-ponds and undrained lands remained), if all the
surface of a considerable extent of country were made calcareous,
and all rapidly putrescent and otherwise offensive matter were pre-
served and kept harmless by being combined with marl, applied
from time to time as required. But it should be remembered that,
as yet, rapid and extensive as has been the progress of marling in
Virginia, there has been no instance of the greater part of any
whole neighbourhood of so much as a few miles in extent being
marled -, nor even of all the surface of any one farm ; and that,
therefore, we have no means of judging by experience of the full
measure of benefit to be derived from such a general change of the
character of the soil. The most that has yet been done anywhere is
the marling of all the cultivated and arable land ; leaving unmarled,
and as much as ever the abundant sources of vegetable decompo-
sition and of disease, all the wood-land, steep hill-sides, and the wet
bottoms. Now, as the remaining wood-lands are generally among
the poorest of our soils, that is, (according to the theory maintain-
ed), soils incapable of combining with and retaining the products
of decomposition — and as they are covered annually with leaves,
which in time all rot and their gaseous products finally pass off into
the air — it follows, that the lands so left must be among the most
fruitful of malaria. It is obvious that the remedy is but partially
and inefficiently in operation, so long as from one-third to one-half

280 EFFECTS UF CALXING ON HEALTH.

of every farm is left unmarlcd, and as free as ever to evolve the
agent of disease. So sure does this opinion seem to me, that I
have commenced acting on it, by marling the wood-land that is not
designed to be cleared for cultivation — and shall continue, as more
necessary labours permit, to do so, until not an acre of the farm
is left without being changed in character by calcareous earth.

It is proper to add, as an opinion founded on but limited expe-
rience as yet, that though the cases of sickness on Coggins Point
farm have cerfUinly diminished very greatly — there not being one
case of late years of bilious disease, where there were twenty
formerly — still that the diseases seem to have changed in kind,
and to have increased in severity and danger. Formerly, there
was almost no sickness except from ague and fever (or, very rarely,
a case of mild bilious fever), from which, though few persons
escaped through the autumn, and some suffered several relapses,
the attacks were rarely dangerous, and required little skill, and
but a few days to cure, for that time. Bad as was this state of
things, it seemed that the ague and fever acted as a safety-valve
to the system, and while it seldom permitted the enjoyment of long-
continued robust health, it prevented the occurrence of more
dangerous or fatal diseases, such as are the most common among
the fewer diseases of what are deemed healthy regions. The fewer
diseases of my adult negroes for the last twelve or thirteen years
have been of a more inflammatory kind, and are not confined to
autumn ; and there have been certainly more severe and fatal dis-
eases, and more that required medical aid, than formerly, when
there was so much more of sickness of one kind, and confined to
one season. In short, it seems that the diseases are no longer (or
but in few cases) those of the low country and of a bilious climate,
but are more like those of the upper country, which, though
occurring but rarely, are generally of a more serious nature. The
facts on which this particular opinion has been formed, are still too
few, and of too short continuance, to attach to them much import-
ance ; and even if they were less doubtful, I have not the medical
knowledge to trace these new effects back to their causes. Still, it
is deemed due to candour, and to the desire for a fair and full in-
vestigation of the subject, even if making against my own views,
that these opinions should be stated. There is no other subject,
than this, taken in general, which more deserves and requires in-
vestigation ; and in the present inchoate state of the discussion,
the expression of even erroneous opinions will not be useless, if it
should serve to elicit more full or correct ones from other sources.

Nothing better than this one subject deserves investigation by
medical men, acting under the direction of government. The ma-
terials for information are now abundant, in the experience and
observation of the numerous farmers who have marled or limed

EFFECTS OF CALXING ON HEALTH. 281

their lands long enough to judge of the effects on health j and
whether upon true or false grounds, the opinion among such per-
sons seems now (1842) almost universal (so far as I have heard
opinions expressed), that the prevalence of autumnal diseases, the
product pf malaria, has been invariably and manifestly lessened
since the lands were in part marled or limed. My indiyidual ex-
perience and observations on this point, now of nine years' more
extent than when the first fruits thereof were stated in a foregoing
part of this chapter, concur with the more general and loose
information derived from" others, in confirming my position. It
sometimes happens that the very fact of an opinion being univer-
sally admitted prevents the obtaining such proofs of its truth as
would certainly have been ready, if the opinion had been questioned
and denied by many sceptics. And such is the state of the pro-
position now under consideration. Even in the few years which
have passed since I first advanced the opinion that the use of cal-
careous manures served to improve health, that opinion has become
so general, and is deemed so certain and unquestionable, by those
persons who have used those manures, that but few facts can be
learned of them sufiiciently exact to serve as proofs — because no
person has deemed it necessary to collect and preserve proofs of
what none doubted. When asking for such proofs, as I have often
done, of cultivators and residents in various parts of the marl
region, I have rarely obtained any, except new declarations, from
every person interrogated, of concurrence and entire faith in the
general opinion that marling or liming had served greatly to abate
the prevalence of autumnal diseases. Such" general belief and con-
fidence in an opinion so recently promulgated, cannot be altogether
founded on error. (1842.)

When my opinions of the beneficial operation of calcareous earth
in soil, or mixed with putrescent matter, in destroying or disarming
the sources of disease, were first published, and until after the
second publication of the same in 1835, I had no knowledge that
similar grounds had been taken by any other person. But since,
in the recent publications of a French writer, M. Puvis, I have
found the same general opinion expressed, and many important
facts given in confirmation. However, while I gladly accept the
important aid of M. Puvis's facts, as proof, I do not admit the cor-
rectness of his reasoning thereupon. Some of the former will be
quoted in the following passages. For his full views, see the
translations of his essays ''On Lime as Manure," and ''On Marl,''
both contained in vol. iii. of the Farmers' Register.

" The results of marling may be considered in a point of view

more elevated, and still more important than that of the fertility

which it gives to the soil ; they may perhaps have much influence

on the healthiness of a country where it" becomes a general practice.

24* ,

282 EFFECTS OP CALX ON HEALTH IN FRANCE.

"Althougli it may not have been yet uttered by others, this
opinion appears founded on strong probabilities, on strong analogies
and precise facts, all of which appear to give it a sufficient cer-
tainty.

" It is known that the calcareous principle is one of the most
powerful agents to resist putrefaction. It is employed to make
healthy places inhabited by men and animals, in which sickness or
contagion is feared ; it serves to neutralize the emanations of dead
bodies undergoing putrefaction ; it destroys the deleterious exhala-
tions which escape from privies, and which sometimes cause the
death of those who are employed to cleanse them.

^'It even seems that calcareous countries are unhealthy only
when they are interspersed with marshes, or when some causes,
foreign to the soil and climate, determine the unhealthiness, as in
countries on the borders of the sea, where the flowing of the tide
and the mingling of salt and fresh waters infect the air, by the dele-
terious emanations of their combination. This cause of unhealthi-
ness is regarded as a certain fact ; for salubrity is generally seen to
appear whenever this mixture of waters is prevented.

" In the valleys of rivers bordered by calcareous mountains,
which enclose unhealthy countries in their interior, insalubrity
commences there only as the calcareous soil, which is attached to
the mountain, gives place to silicious soil. In the same plain,
and far from a mountain, salubrity is seen to diminish in the same
proportion that the calcareous soil of the surface does ; and the
communes of Brcsse, which have an abundance of marly or calca-
• reous soils, are much more remarkable for their salubrity than those
on the white lands (^terrain hlanc^'). While the ponds of Dombe,
which are on the silicious soil, appear to be one of the greatest
causes of unhealthiness, those of Bresse, which are on calcareous
lands, do not show such effects in the country where they are found ;
so, likewise, the ponds of the country situated between the Veyle
and the Beyssouze, to the north-west of Bourg, which are generally
on calcareous soil, do not appear to injure the healthiness of the
country in any manner.

" For the support of this system, we will also cite the ponds of
Berri on calcareous soil, whose emanations have nothing unhealthy;
the laying dry of the ponds of Parragay, in the canton of Lignieres,
has added nothing to the healthiness of a calcareous country na-

* The reader of M. Puvis's essays on lime and marl, which were inserted
in Yol. iii. of Farmers' Register, may remember that this provincial term
and others (plateaux argillo-silicicux, &c.) were there used to designate a
peculiar kind of soil, destitute of calcareous matter, stiff, intractable, and
poor — and which seems precisely of the character of the poor ridge lands
of lower Virginia, to which calcareous manures are so peculiarly adapted.
— Translator,

EFFECTS ON HEALTH IN FRANCE AND ENGLAND. 283

turally healthy. And* in the same canton, the pond of Villiers,
which is said to be seven leagues in circumference, does not cause
diseases on its borders. Besides, during the month of August, the
water of the ponds on calcareous soil does not become blackish,
as often happens in silicious ponds. The water would then be
made wholesome by the calcareous principle, in the same way as
their emanations.

" In j&ne, Dombe and Sologne, and a number of other countries,
are unhealthy, and subject to intermittent fevers, without being
marshy; but their soil is likewise silicious, and the land moist.
Puisaye, and a part of Bresse, in similar land, which contain little
or no calcareous soil, have also many autumnal fevers.'' — Transla-
tion from ^' Essai sur la 3Iarne."*

In addition to these opinions of Puvis, and his facts in regard to
France, I may add the later testimony of two other eminent agri-
cultural writers, whose information may be inferred to have been
derived from the experience of England and Scotland. In a small
pamphlet written by Sir John Sinclair, and dated 1833, on the
means for preventing the ill effects of malaria,-\- he names as
among the most important the use of calcareous manures. '^ The
effect of burnt limestone,'' he adds, "in improving the quality of
the soil is hardly to be credited. It either absorbs any noxious
matter, or annihilates any deleterious properties it possesses ; and
it may be relied upon as an established fact ' that a soil full of
calcareous matter never produces an unwholesome atmosphere.' "
And again : " The introduction of immense quantities of calcareous
matter into the soil not only contributes to its improvement, but
is the best means of preventing malaria.'^

Professor Johnston, still more recently, speaks as follows : " The
liming of the land is the harbinger of health as well as of abun-
dance. It salubrifies no less than it enriches. . . . The lime
arrests the noxious effluvia which tend to rise more or less from
every soil at certain seasons of the year, decomposes them, or causes
their elements to assume new forms of chemical combination, in
which they no longer exert the same injurious influence on animal
life." — Lectures, &c., pp. 392-3.

Thus there is now good evidence and high authority for this
opinion, which I at first advanced with much hesitation and fear ;
and which then met with distrust or incredulity with almost all

* This work was published in Paris in 1826. The first known (and pro-
bably still the only) copy brought to America, was in 1835, by my order,
made soon after seeing M. Puvis's essays on lime and marl in the '^A?inales
d' Agriculture Frangaise," both of which I translated and published in the
Farmers' Register, vol. iii.

t This pamphlet was republished in the Farmers' Register, yoI. i., p.
556.

284 NATURAL CONDITIONS OP MARL BEDS.

who had not experience or information of the sanitary influence of
calcareous manures. ""

But however strong the conviction of these authors of such
effects of calcareous manures, they offer no satisfactory explanation
of the manner in which the effects are produced. But whether
lime, in soil, exerts its health-preserving power by " arresting the
noxious effluvia which tend to rise from every soil,^' &c. — or by
absorbing noxious matter, or annihilating any deleterious properties
it possesses" — or, according to my previously expressed doctrine,
by the power of lime (calx) to combine with the first results of
putrefaction, and so fix them in the soil, there to serve only as food
for plants — the end is the same, of converting to the purpose of
fertilization and production what would otherwise escape into the
air in the form of pestilential gases.

The important facts, recently made known by Dr. Wight, as
stated in a previous chapter, that the calxing of soil causes the
plants grown thereon to absorb from the atmosphere much in-
creased quantities of carbonic acid, and to evolve proportionately
increased quantities of oxygen gas, serve to add greatly to the be-
fore supposed sanitary operation of calxing land. Both the as-
serted actions, co-operating, are abundant and satisfactory causes for
the beneficial effects to health ; and of which effects there can be
no longer room to doubt, seeing the testimony adduced from France
and England, in addition to all that I had before offered.

CHAPTER XXVI.

THE EXCAVATION OF MARL PITS, AND CARRYING OUT AND APPLY-
ING OF MARL.

The natural features of marl beds, and their exposures, are dif-
ferent at almost every locality; and therefore no one manner of
working will suit precisely for different diggings. Still, all the marl
beds of Virginia may be classed under three heads, in reference to
the excavation and removal of the marl.

I. The first class is of marl exposed (or "cropping out") high
up on hill-sides, with but little overlying earth to remove for large
excavations of the marl below — the marl and the adjacent ground
dry and free from springs — and the proper sites for roads, leading
to the fields, either descending, or nearly level, or with not much
ascent. Marl so lying is often of the richest kind, containing from
60 to more than 80 per cent, of pure shelly matter, and that mostly

DRY AND WET MARL BEDS IN HILLY LANDS. 285

finely divided. Many of these richest and also almost easily worked
bodies of marl are iu the middle range across the rivers and the
marl region of Virginia; for example, in the counties of Nanse-
mond, Isle of Wight, Surry, James City, York, New Kent, and
the lower part of King William. Under these very favourable cir-
cumstances, special directions for working such marls would be
superfluous. The labours required are as simple, and almost as
cheap, as the digging and carting away -of earth from a hill-side to
construct a mill-dam.

II. The second class of exposures and diggings is usually of much
poorer marl, and attended with much more difficulty and cost than
the preceding. In high lands, cut through by deep ravines, or
narrow valleys, the natural " out-croppings" of the marl are usually
low down the sides, or at the bottoms of steep hill-sides, the marl
often wet from springs oozing over the top, and also from water
percolating slowly through the mass of marl. The lower adjacent
ground^^ also wet, by springs or streams. The overlying earth is
very thick, and costly to remove ; and a steep or a long-ascending
road is required to draw the marl to the higher lands where it is to
be applied.

In hilly lands, the bed of marl usually "crops out" on the
swells, or convex curves of the hill-sides, and thus is naturally ex-
posed to view. If this is at a considerable elevation above the bot-
tom of the ravine or narrow valley which is usually at the foot of
the hill, the marl will generally be dry. But its being dry will
depend on some one of the following conditions : 1st. When the
overlying beds of earth have not enough extent of surface to allow
springs to be formed by infiltration of rain-water; or there is no
impervious bed, either of the marl or its overlay, on which spring
water can be borne, if it flows from distant sources : 2d. Or even
if there be any such impervious and water-bearing stratum, that its
" dip" is in a direction leading from the " out-cropping" of the
marl; so that all spring- water, or infiltrated rain-water, must
necessarily flow in a direction leading from the exposure. In the
reversed circumstances, the marl will be wet, and proper drainage
of the pits will be necessary. Bodies of marl of this second class
are most common in the high and broken lands lying between the
localities named above, and the falls of the rivers.

III. The third class of marl generally belongs to the more level
lands, but in some cases to the low bottoms and ravines of the
highest and most hilly. But in either case, the surface of the marl
is lower than that of all the surrounding land (unless perhaps of
the mere outlet for the water) ; and the excavations and the roads
all need careful and perfect drainage.

I will now return to the consideration, principally, of excavations
of the second class ; though they will in part suit also for the third
class.

286

EXCAVATION OF WET MARL.

There is a general dip of the marl to the east, through lower
Virginia. But this so slight, and irregular withal, that it does not
always direct the course of the spring-water above according to the
general course of the dip. At each particular locality, the marl
stratum may be considered as nearly horizontal. The upper sur-
face of the dry marls is often very irregular in outline, owing to
the washing operation of ancient currents of the sea, or later floods,
and whirpools, subsequent to the deposition of the beds of shells.

Unless very sandy and poor, and also oozy, all our marls are
sufficiently firm before being dug, for the sides of a pit to stand
secure when cut perpendicularly. The dry beds, of course, are
much easier to be worked than the wet. Where the bed is dry,
no directions are required for pit-work; except that the pit shall
•be long enough to allow the carts to descend therein, and to rise
out, loaded, on a graduated and gently sloping road-way. This will
obviate the necessity existing when pits are short and steep, of
twice throwing the marl — first out of the pit, and afterwaids into
the carts. No machine or contrivance yet known will serve as
well for cheapness to raise marl from the bottom of a pit, or dig-
ging, as a cart ; and no care or labour will be lost in draining and
enlarging the pit, and graduating the ascent out from it, if there-
by carts can easily and safely draw from the bottom. These re-
marks may apply to any excavation made by sinking pits below
the level of the general surface.

Profile J or cross-section of marl diggings^ of class 11.

Explanations.
5, a, Face of hill-side.
a, Stream, or bottom of valley.
p, c, f, h, m, Bed of marl, out-cropping at c.
m, m, Bottom of workable marl,
o, d, ff, Overlying earth.

I will describe an ordinary case of hill-side excavation.

EXCAVATION OP MARL IN HILLY LANDS. 287

Suppose tlie marl to " crop out/' or otherwise to come near to
the surface near the foot of a high hill-side (as at c), a ravine and
stream being at the bottom (s), and table-land at the top of the
hill-side, over which the marl is to be carted to the fields, after
rising the hill-side by a graduated road. These are common natural
features of marl localities, in hilly lands (and of class II). The
out-crop, or natural exposure of the marl (c) is on a convex curve
of the hill-side. The first operation is to clear off the little over-
lay of earth, -from above the out-crop (o), so as to uncover a suffi-
cient space for digging and carting (o, c.) This space should be
(if practicable), 15 feet across, of horizontal width, to permit sin-
gle-carts to turn upon ; and as long (with the course of the stream)
as the ground may permit, say 30 feet or more. This small amount
of overlying earth (o) is easily disposed of, by being thrown into
the ravine, or across the stream. The uncovering reaches to the
top of tiie marl stratum, which is supposed 12 feet thick ; of which,
8 feet are above and 4 below the level of the stream. A road ia
next laid off, graduated to best advantage, and constructed, de-
scending from the upper table land to the uncovered marl, the lower
end of the road being on a level about 1 foot higher than the
stream, and of course 5 feet above the bottom (m, m), of the marl
fit for use. ■ (The lowest part is usually too poor, and sometimes
too much affected by water, to be worth being removed.) If springs
ooze out over the top of the marl, a little trench (i?) of about 4
inches wide and as many deep, must be made along the back line
of the uncovering, to cut off and convey away the spring water.
The uncovered and drained marl (c, t,) is then dug and carted out ;
the work being so conducted as to level the surface, and enable the
carts as soon as the surface is enough lowered, to pass over, turn
about, and be loaded upon the marl. When the whole space has
been dug down to the level of the lower end of the road (a, t,)
then a perpendicular pit should be dug at the end of the area
farthest from the descending road, and across its whole width.
This pit (p p) will be 15 feet long, about 6 to 9 wide, as may
be most convenient, and 5 deep when finished to the bottom. The
carts turn on the area (a, t,~) and are loaded at the edge of this
pit. When finished, another similar pit is dug alongside; and
others " in succession, until the whole area of the first uncovered
marl has been so pitted out. The overlay (d) is then dug and
thrown off from the next range or section of marl (/), so as to
uncover another width of 15 feet. The removed earth here (d)j
where highest, might have been more than 10 feet thick. But the
space excavated for the first range of marl (cj?) has more than
room enough to receive all this earth.

The carts now have to be supplied from the second range of
marl (/). As this is throughout of the full thickness of the bed,

288 REMOVING OVERLYING EARTH. ^

and rising 7 feet above the lower end of the road, it may be con-
venient to make a branch to the road running on a level to the top
of the marl. This branch will be used iintil the lowering of the
upper marl, by its excavation, shall render the lower branch of the
road again more suitable. This range of the marl is drained,
worked out to the level of a f, and then the lower part (r, r,) ex-
cavated in successive perpendicular pits, in the same manner as the
previous range. Then a third range of overlay (</) is dug and
thrown off into the finished previous excavation (/, r, r) ) and by
its increased thickness perhaps fills it up as high as the top of the
marl stratum. But this does no serious harm. It will however
require the leaving a wall of marl (x, x) when digging out the
marl belo\^ Qi) to keep out the earth and water of this heap ; and
also cross walls for support, between the lower perpendicular pits.

It will now be much more laborious to uncover another range
(at i), still deeper in the hill-side ) and it will become a question
for the operator to decide, whether to proceed farther with this
work here, or to begin another uncovering in some more favourable
situation.

For any extensive operation, it is much cheaper to take off a
cover of earth 20 feet thick, to obtain marl of equal depth, than
if both the covering earth and marl were only three feet each.
Whether the cover be thick or thin, two parts of the operation
are equally troublesome, viz. to take off the mat of roots, and per-
haps some large trees on the surface soil, and to clean off the sur-
foce of the marl, which is sometimes very irregular. The greater part
of the thickest cover would be much easier to work. But the most im-
portant advantage in taking off earth of ten or more feet in thick-
ness, is saving digging by causing the earth to come down by its
own weight. If time can be allowed to aid this operation, the
dryest earth will mostly fall, by being repeatedly undermined a
little. But this is greatly facilitated by the oozing water, which
generally fills the earth lying immediately on beds of wet marl. In
uncovering a bed of this description, for one of my early operations,
where the marl wa» to be dug 14 feet, and 10 to 12 feet of earth
to remove, my labour was made ten-fold heavier by digging
altogether. The surface bore living trees, and was full of roots —
there was enough stone to keep the edges of the hoes battered —
and small springs and oozing water came out everywhere, after
digging a few feet deep. A considerable part of the earth was a
tough, adhesive clay, wet throughout, and which it was equally
diflacult to get on the shovels, and to get rid of Some years after,
another pit was uncovered on the same bed, and under like circum-
stances, except that th^ time was the last of summer, and there
was less water oozing through the earth. This digging was begun
at the lowest part of the earth, which was a layer of sand, kept

DRAINING AND WASHING WET MARL PITS. 289

quite wet and soft by the water oozing through it. With gravel
shovels, this was easily cut under from one to two feet along the
whole length of the old pit, and, as fast as was desirable, the upper
earth, thus undermined, fell into the old pit ; and afterwards, when
that did not take pla<;e of itself, the fallen earth was easily thrown
there by shovels. As the earth fell separated into small but com-
pact masses, it was not much affected by the water, even when it
remained through the night before being shoveled away. No dig-
ging was required, except this continued shoveling out of the
lowest sand stratum ; and whether clay, or stones, or roots, were
mixed with the falling earth, they were easy to throw off. The
numerous roots, which were so troublesome in the former operation,
were now an advantage ; as they supported the earth sufficiently to
let it fall only gradually and safely ; and before the roots fell, they
were almost clear of earth. The whole body of earth, notwith-
standing all its difficulties, was moved off as easily as the dryesfc
and softest could have been by digging altogether. The thicker
the overlying earth, the greater is the facility of undermining, and
■causing it to fall by its own weight.

In working a pit of low-lying and wet marl, covered and sur-
rounded by higher ground (class III.), nopains should be spared to
drain it as effectually as possible. Very few beds of marl are
penetrated by veins of running water which would deserve the
name of springs ; but water generally oozes very slowly through
every part of wet marl, and many small springs often burst out
immediately over its surface. After the form of the pit and situa-
tion of the road are determined, a ditch to receive and draw off all
the water should be commenced lower down the valley, as deep
as the bottom of the area where the carts are to stand is expected
to be made ; and the ditch opened up to the work, deepening as it
extends, so as to keep the bottom of the ditch on as low a level as
the bottom of the area. It may be cheaper, and will serve as well,
to deepen this ditch as the deepening of the pit proceeds. After
the surface of the marl is uncovered for the full size intended for
the area (which ought to be at least large enough for carts to turn
about on), a little drain of three or four inches wide, and as many
deep (or the size made by the grubbing-hoe used to cut it), should
be carried all around to intercept the surface or spring-water, and
conduct it to the main drain. The marl will now be dry enough
for the carts to be brought on and loaded. But as the digging
proceeds, oozing water will collect slowly ; and, aided by the wheels
of loaded carts, the surface of the firmest marl would soon be
rendered a puddle, and next a quagmire. This may easily be pre-
vented by the inclination of the surface. The first course dug off
should be much the deepest next the surface drain (leaving a mar-
gin of a few inches of firm marl, as a bank to keep in the stream),
25

290 WORKING WET MARL TITS,

SO that the digging shall be the lowest around the outside, and
gradually rise in level to the middle of the area ; or next to the
old diggings, now heaped with the later removed overlay. What-
ever water may find its way within the work, whether from oozing,
rain, or accidental bursting of the little surface drain, will run to
the outside, the dip of which should lead to the lower main drain.
After this form has once been given to the surface of the area^
very little attention is required to preserve it ; for if the successive
courses are dug of equal depth from side to side, the previous
shape will not be altered. The sides or walls of the pit should be
cut (in descending), something without the perpendicular, so that
the pit is made 12 or 15 inches wider at bottom than top. The usual
firm texture of marl will prevent any danger from this overhanging
shape, and several advantages will be gained from it. It gives more
space for work — prevents the wheels running on the lowest and
wettest parts — allows more earth to be disposed of, in opening for
the next pit — and prevents that earth from tumbling as easily into
the next digging, when the separating wall of maid is afterwards
cut away. The upper and larger drain of the pit, which takes the
surface water, will hang over the small one below, kept for the
oozing water. The former remains unaltered throughout the job^
and may still convey the stream when six feet above the heads of
the labourers in the pit. " The lower drain of course sinks with the
digging. Should the pit be dug deeper than the level of the main
receiving ditch can be sunk, a wall should be left between, and the
remainder of the oozing water must be conducted to a little basin
near the wall, and thence be bailed or pumped into the receiving
ditch. The passage for the carts to ascend from the pit should be
kept on a suitable slope ; and the marl forming that slope may be
cut out in small pits, after all the other digging has been completed.

If the marl is so situated that carts cannot be driven as low as
the bottom, either because of the danger of flooding, or that the
ascent would be too steep for sufficiently easy draught, then the
area must be cut out in small pits, as before stated, beginning at
the back part, and extending as they proceed^ towards the road
leading out of the pit.

It is the less required to extend directions for the mode of work-
ing low-lying marl, covered and sourrouuded by higher land, and
by its springs, because large excavations under these difficulties,
will be described in a later part of this work, and the w^ole course
of procedure minutely stated.

In some cases, either because of the great liability of the over-
lying oozy earth to CDve and fall in, and thus continually to choke
the surrounding marl drains, or of rain-floods to fill and damage
the excavations, it is too hazardous to leave diggings unfinished for
any length of time ; and still more for the unfinished work to be

CRANE FOR RAISING MARL BY HORSE POWER. 291

suspended through winter. In such cases, it is better to bestow
more labour to obtain security. Under such circumstances perpen*
dicular pits should be sunk first through the over-lay and then the
marl. If not too great a height, the marl, as dug, should be
thrown to the top of the remaining firm earth, there to be thrown
into and removed by the carts. When the digging is carried so
low that the throwing exceeds 10 feet in perpendicular height, a
scaffold should be made, or a shelf of marl left, at the side
of the pit next to which the carts approach, and at a convenient
height for the remainder of the digging. The lower marl will be
thrown first upon the scaffold, thence to the surface of the ground
above, and then into the carts. Thus, the marl may be thrown up
from the bottom of the bed, if that be not more than 20 feet be-
low the surface, for loading. The length and breadth of such pits
should not be greater than to permit each pit to be finished in a
few days after its commencement. Then an adjoining like space
may be uncovered, the earth being thrown into the previous dig-
ging, and the marl excavated in like manner. Should a flood of
rain-water, or the caving in of wet earth fill such a pit, when the
digging had not been sunk but a few feet, the damage may be
remedied and the remaining marl saved. Or if but a few feet
thickness of marl be left, and is covered by earth or water in
too. great quantity to be worth clearing out, then the loss of the
bottom marl will not be very important.

For such situatit)ns as these, in some cases lifting machines have
been used successfully. One used by Wm. Carmichael, Esq., of
Maryland, was described by him in a communication to the Far-
mers' Register, as follows :

" In your ' Essay on Calcareous Manures,' you give instructions
for digging and carting marl. This method I pursued for many
years, but found the labour hard on my hands, and tedious. Marl
here is generally found in deep ravines or in wet grounds. My
operations have been slow, from the difficulty of making firm and
lasting ways, and the labour of ascending steep hills. Last winter
I made a model, and this spring I built a machine for raising marl,
to be worked by a horse. I have been using it to advantage, and
now send you a draught of it, as it may be useful to those
who have wet marl pits like mine. By means of a pump to throw
off the water, pits may be worked at a considerable depth ; and
even if marl is dry, but lies deep, I think the crane might be used
to advantage. I user two boxes, and by means of hinges and a
latch the marl is discharged from the bottom. I have double
blocks; the rope passes through the swoop about eighteen inches
from the end, and runs down to the post which supports the swoop,
and passes through it on a small roller, and in like manner through
the next post to the cylinder, to which a reel is attached to increase
the motion. The post which holds the swoop and the cylinder,

1292 CRANE FOR RAISING MARL BY HORSE POWER.

runs on iron pins let into thimbles. The lever is in two pieces,
one fastened in the cylinder with a groove at the end, into which
the other is let, and secured by a sliding iron clamp. When the
marl is discharged from the box, and the swoop swung round over
the pit, in nautical phrase, by unshipping the end of the lever, the
rope unwinds, and the box descends without moving the horse.
The circle in which the horse travels ought to be twenty-one feet in
diameter. The second and third posts are supported by side braces.

'^ The cost of the machine is small, though I cannot make an
exact estimate. The carpenter who did the work was hired by the
day on the farm, and was taken off with other jobs; but his bill
could not exceed eight dollars. The cost of the iron-work was
ten, and one hundred and sixty-five feet of inch rope, at eighteen
and a half cents a pound. The timber, taken from my own woods,
may be estimated at five dollars. The rope I find soon wears out,
and I intend to supply its place with a light iron chain.

*^ When the marl is uncovered, with one efficient hand in the pit
and a less efficient one to discharge the boxes and drive the horse,
five hundred bushels may be raised in a day. The work is not
oppressive to the labourers. The teams stand on high, dry ground;
no sloughs to plunge through, and no hill to climb. The swoop
is turned by a small rope over the carts, and the marl immediately
discharged into them. I work four carts, with two sets of oxen to
each. They came out of the winter lean and weak ; and now, with
green clover for their food, at the distance of a half to three-quarters
of a mile I draw out from four to five hundred bushels a day, and
my oxen have improved. My work goes on with ease and expedi-
tion, without stoppage to mend roads, or to clean ditches."

The machine which will be described below is used at Fortress
Monroe for raising sand from the fosse to fill the ramparts ; and
has been found by experience to be the best contrivance of all
which have been tried for that operation, and for which an immense
amount of labour was necessary in constructing the defences of the
fortress. Precisely the same manner of operation is required for
raising marl from deep pits, and there can be no doubt of this
being a more effective machine for that purpose than any worked
by hand. The force applied is the weight of the labourers, on

MACHINE FOR HAND LABOUR.

298

±he principle of the tread-mill, which, though heavy labour, is the
most effective manner in which the power of men can be applied.
I am indebted for the suggestion of this machine for raising marl
to the observation and scientific knowledge of mechanics of my
friend Professor M. Tuomey, and also for the following description,
and the drawings for the engraved figures. Mr. Tuomey, when
making a transient visit to the fortress, had seen the machine at
work ; and after reading in the foregoing part of this work the
remarks on the different modes of raising marl, and having wit-
nessed some of the usual modes in practice, this machine and what
he had seen of its power appeared greatly superior, wherever cir-
cumstances may require the use of machiuery. Upon being thus
informed, I applied to Dr. Robert Archer, U. S. A. Surgeon at
Fortress Monroe, for a rough plan, and accurate statement of the
dimensions of the machine, both of which he kindly furnished;
and with the aid of these, Mr. Tuomey has been enabled to give
such particular description and correct delineation as will serve for
full instruction for the building and working of the machine.

Fig. 1.

**1. Figure 1 is a side view, in perspective.

i, i, The base, consisting of 3 pieces of scantling, each 12 feet long, and
11 Indies by 5, notched on to each other about 6 inches from the end, so
as to be flush on top, forming an equilateral triangle.

e, The principal post 8 feet, 8 by 6 inches, secured to the base, and braced
by the braces /. Near the top of this post 2 iron sheeves or pulleys are
placed, one on each side, and secured by pieces spiked over them. The
chains pass over these pullej^s.

/. 2 braces 11 feet long, 4 inches by 6,

7<, h, Two uprights, in which the gudgeons of the wheel turn; they are
bolted to the base and connected at the top by the piece ^,10 feet 6
inches long, 4| by 6 inches, which also serves as dTliand rail for the men
to steady by when working on the wheel. These uprights are furtheu
secured by cross-pieces connQcted with the braces, and bearing in front
25*

294

MACHINE FOR HAND LABOUR.

and rear of the wheel two steps on which the men stand as they go on or
off the wheel.

w. The wheel 4 feet in diameter, the steps 3| feet long 8 inches wide, made
of \\ inch plank. The ends of the wheels are formed of two thicknesses
of inch plank placed crosswise, the inside being grooved to receive the
steps which are placed about 8 inches apart. The axle of the wheel is
10 feet 6 inches long and 8 inches in diameter, the portion round which
the rope winds is enlarged, so as to suit the force employed on the wheel,
or the weight to be raised, by nailing on strips of plank, over which a
few turns of old rope may be placed to prevent the slipping of the chain.

To prevent confusion, only one crane (or arm) is represented in this figure.

The crane post is represented as turning on two iron pivots in pieces s, s,
one bolted to the principal post e, and the other spiked to the base. The
crane post is 6 inches square.

a. The crane jib, 7 feet 6 inches long, 6 by 7 inches.

h. The strut to the jib, 8 feet 6 inches long, 4 by 6 inches. Near the ex-
tremity of the jib an iron sheeve is fixed over which the chain passes.

c. Is a three-quarter inch rod of iron secured to a by means of a staple,
and having a hook at the other end, which drops into a staple at i. This
rod serves the double purpose of a stay and a guide, by which (when
unhooked) the arm is drawn to one side for the purpose of landing the
box. When fixed as represented in the drawing, it serves to retain the
crane in its proper position. When the box is raised the rod is unhooked,
and by means of it the box is landed. ^

Fig. 2.

Figure 2 is a front view, showing the relative position of the cranes, which
are represented as turned aside. The chain is seen winding around the
axle. It is evident that the men must pass to the opposite side of the
wheel as each box is drawn up.

yy. Represents 2. views of the boxes, which are square and may be each
about 21 inches every way. They will then contain nearly 6 cubic feet
each. They are suspended by two pins, placed a little below and to one

ROAD-MAKING. 295

side of the centi'e so as to turn over and empty themselves when a small
iron pin seen at /, figure 2, is withdrawn. Three men can be employed
to advantage at the wheel, two remaining on, whilst the third gets off to
land the box. Should the box not be heavy enough, the diameter of the
axle can be enlarged, so as to make up in time what is lost in weight.
Should it be too heavy for the force employed, the diameter may be les-
sened."

The above dimensions of timbers were those of the particular
machine measured by Dr. Archer; but they vary in all the machines
of this kind used at the fortress. The length of the arms of course
should be proportioned to the height to which the loaded buckets
are to be raised. For marl, any sized timbers on band, or logs,
that are long enough, would serve for the base (i, i.) It is how-
ever desirable that the machine should be as light as is consistent
with strength, for the greater facility of moving it ; and for strength
alone (as in all other machines) the large size of timbers is of less
importance than their being well put together. Two thick and
narrow planks, firmly spiked together, and with a space left be-
tween of proper size for the shelve to, play in at the upper end,
would be a cheaper substitute for the;<Jib cd. When carts are re-
moving the marl at the same time it is raised, there would be much
advantage gained in having the boxes of such size as to be emptied
into the carts, and the measure or load of a box, to be some aliquot
part of the loads for the carts.

Machines of this kind will be required, and will be most profita-
ble, whenever marl is to be taken from deep and wet pits, and in
extended operations.

Making Roads.

On high and hilly land, marl is generally found near the bottom
of ravines, and separated from the field to which it is to be carried
by a high and steep hill-side. The difiiculty of cutting roads in such
situations is much less than any inexperienced person would sup-
pose. We cannot get rid of any of the actual elevation — but the
ascent may be made as gradual as is desired, by a proper location
of the road. The intended course must be laid oif by the eye, and
the upper side of the road marked. If it passes through woods,
it will be necessary to use grubbing hoes for the digging. With
these, the digging should be begun at the distance of four or five
feet below the marked line, and carried horizontally onward to it.
The earth so dug is to be pulled back with the broad hoes, and
laid over a widWi of three or four feet below the place from which
it was taken. Thus the upper side of the road is formed by cut-
ting down, and the lower side by filling up with the earth taken
from above.

290 ROAD-MAKINe.

The annexed figure will prevent these directions being misunder-
stood. The straight line from a to h represents the original slope
of the hill-side, of which the whole figure is a section. The upper
end of the dotted part of the line is in the mark for laying ofif the
upper side of the road. The upper triangle is a section of the
earth dug out of the hill-side, and the lower triangle of the parfc
filled up by its removal. The horizontal line is the level of the
road formed by cutting in on the upper, and filling up on the lower
side. After shading the r6>-d roughly, the deficiencies will be seen,
and may be corrected in the finishing work, by deepening some
places and filling up others, so as to graduate the whole properly.
A width of ten feet of firm road will be sujQ&cient for carting marl
up a short hill.

If the land through which the road is to be cut is not very steep,
and is free from trees and roots, the operation may be made much
cheaper by using the plough. The first furrow should be run along
the line of the lower side of the intended road, and turned down
hill ; the plough then returns empty, to carry a second furrow by
the first. In this manner it proceeds, cutting deeply, and throwing
the slices far (both of which are easily done on a hill-side), until
rather more than the required width for the road is ploughed.
The ploughman then begins again over his first furrow, and ploughs
the whole over as at first, and this course is repeated perhaps once
or twice more, until enough earth is cut from the upper and put on
the lower side of the road. After the first ploughing, broad hoes
should aid and complete the work, by pulling down the earth from
the higher to the lower side, and particularly in those places where
the hill-side is steepest. After the proper shape is given, carts, at
first empty, and then with light loads, should be driven over every
part of the surface of the road until it is firm. If a heavy rain
should fall before it has been thus trodden, the road- would be ren-
dered useless for a considerable time.

IMPLEMENTS; CARTS AND TEAMS FOR MARL. 297

Implements and Means for facilitating the Labours — Application

of Marl

These directions are mostly suited for greater difficulties than
usually occur, though they are such as attended most of my labours
in marling. In the great majority of cases, there will be less
labour, and care, and skill required, because there will not be en-
countered such obstacles as high and steep hills to ascend, thick
over-lying earth to remove, or wet pits and roads to keep drained.

In large operations and in dry and compact marl, much labour
of digging may be saved by slightly undermining the face of a per-
pendicular body of marl, and then S]3litting off large masses, by
driving in a line of large wooden wedges on the upper surface.

For very hard marl, narrow and heavy pickaxes are the best dig-
ging implements. For softer marl, though still of close and com-
pact texture, heavy and narrow grubbing hoes are better. They
should weigh near or quite 7 lbs. when new, and have the cutting
edge 3 to 82- inches. Gravel shovels (with rounded points and
long handles), of the best quality, are the cheapest and most effec-
tive tools for throwing out the marl, and loading the carts, as well
as for afterwards spreading the heaps in the field.

Tumbrel or tilting carts, drawn by one horse or mule, are the
most convenient for conveying marl very short distances ; and even
for longer distances, if on hilly roads and fields. Every part of
such carts should be as light as will serve for strength, and the
body should be so small as to hold only the load it is designed to
carry. This enables the drivers to measure every load; which
advantage, on trial, will be found very important. If carts of
common and much larger sizes are used, the careless labourers will
generally load too lightly, and yet will sometimes injure the horse
by too heavy loading. The small-sized cart-bodies prevent both these
faults. Their loads cannot be made much too heavy ; and if too
light, the deficiency is detected at a glance. When there is much
or steep ascent in the carriage way, 5 heaped bushels of ordinary
wet marl, or 6 of dry, will make a full load for a good mule, or
ordinary horse. The larger quantity may be put in by heaping
somewhat above the level of the cart. The greatest objection to
these carts is that they are too small to carry loads of anything but
marl. On roads nearly level, tumbrels drawn by two mules are
much preferable. There is the saving of another driver, and the
cost and weight of another cart ; and though the cart is large and
heavy, it is so much lighter than two small carts, that two mules
together in the former, will draw full as much weight as if separate
and with the latter. The larger carts should hold about 15 heaped
bushels of marl, when the load is level with the top of the body ;
and which may bo increased to 18 or 19 bushels (the proper load

298 DROPPING AND SPREADI]<fG MARt.

for two mules on level land and firm roads) by heaping. Two
mules together will draw this load, or about 1900 lbs. ; or one
mule, in a light cart, 9 bushels, as easily as the latter will draw 5
bushels on hilly land. But on hilly land, two-mule carts cannot
well be used. For when drawing up a hill, if one mule ceases to
pull for ever so short a time, the whole load, and a doubled labour,
is put upon the other mule, which is thus over-strained, and taught
to balk, if not otherwise damaged.

Strong labourers are required for digging and shovelling marl.
Boys of 12 to 14 years old may drive single-mule carts. The
animals kept regularly at such hauling soon become so gentle and
tractable, that very little skill or strength is required in the driver.
But for a two-mule cart, an active and careful young man should
drive, because his strength is required at some times, and his judg-
ment and care always to load properly, and to make the mules draw
equally.

One of the most general and injurious errors in marling, is the
unequal and irregular spreading of the marl on the land. From
this cause it often happens that there is too much and too little
marl applied to the same quarter-acre; and sorrel still remaining
and growing, and ^' marl-burnt" corn, may be seen not many yards
apart. The only effectual means which I have found to attain any-
. thing like equal distribution, has been to measure by stepping, and
marking with a hoe, each distance for a heap to be dropped. This
has been done by myself for much the greater quantity of all the
marl I have had carried out ; as I never could have the measuring
and marking of distances done with sufficient accuracy by the dri-
vers. If the field had been left in beds, or the rows of the last pre-
vious ploughing are visible, it will much facilitate the marking.
Otherwise, rows must be marked by the plough in one direction,
or measuring poles must be set up at each extremity of the rows
for marl, to mark the cross-distance as well as to guide the direction
of the rows. The thus placing the heaps at regular or average
distances is the best security for regular distribution of the marl
in spreading. But, nevertheless, the latter operation ought to be
carefully watched, and made as uniform as will serve for thorough
and equal diffusion through the soil, with the subsequent aid in
tillage, of ploughing and harrowing.

Some extensive marlers, before commencing on a field, have it
marked off by a plough for the placing of the heaps of mark If
the land is in beds, cross-furrows only are needed. If the surface
is smooth, it must also be marked-at right-angles. In either case,
the field is thus marked off into rectangular spaces, in each of which
a heap of marl is dropped, and over the whole of which space it is
afterwards to be spread. But I found this mode more objection-
able than the former. The drivers have so much latitude, that

MARLINa TABLES.

299

they are very careless as to where they drop their heaps within
each rectangle; and the spreaders have more labour to distribute
the marl equally, and therefore are more apt to neglect it. Besides,
it is often requisite to alter the distances of the heaps, either because
of change of soil, or because of change in the sizes of the loads,
owing to altered condition of the roads.

Marling Tables and Estimates.

The following tables may be useful in facilitating calculations,
and promoting the important object of applying marl in equal and
uniform quantities, according to the quality of the marl and the
wants of the soil ; which object, however, is generally so little re-
garded, that few persons attempt by calculation to reach any of the
results which these tables are designed to show by mere reference.

Table I. Showing the number of cubic feet of dug marl [as compressed by its
weight in the loaded carts), necessary to furnish one per cent, of carbonate
of lime to the acre of soil, for the ploughed depths stated :

Marl contain-

ing of carb.

3 inches.

4 inches.

5 inches.

6 inches.

7 inches.

8 inches.

lime.

per cent.

cubic feet.

cubic feet.

cubic feet.

cubic feet.

cubic feet.

cubic teet.

10

1089.

1452.

1815.

2178.

2541.

2904.

20

544.5

726.

907.5 •

1089.

1270.5

1452.

30

363.

484.

605.

726.

847.

968.

40

272.25

363.

453.75

544.5

635.25

726.

50

217.8

290.4

363.

435.6

508.2

580.8

60

181.5

242.

302.5

363.

423.5

480.66

70

155.57

207.43

259.28

211.14

363.

414.86

80

136.12

181.5

226.87

272.25

317.62

363.

90

121.

161.33

201.66

242.

282.33

322.66

100

108.9

145.2

181.5

217.8

254.1

290.4

Table II. Showing the number of even bushels of marl, as compressed by its
weight in the carts, necessary to furnish one per ce?it. of carbonate of lime to
the soil, for the tilled depths stated :

Marl cont'ing
per cent of
carb. lime.

3 inches.

4 inches.

5 inches.

6 inches.

7 inches.

8 inches.

10

bushels.
875.1

bushels.
1166.8

bushels.
1458.5

bushels.
1750.2

bushels.
2041.9

bushels.
2333.6

20

437.55

583.4

729.25

875.1

1020.95

1166.8

30

291.7

388.93

486.17

583.4

680.63

777.87

40

218.77

291.7

364.62

437.55

510.47

583.4

50

175.02

233.36

291.7

350.04

408.38

466.72

' 60

145.85

194.46

243.08

291.7

340.31

388.93

70

125.01

180.97

208.36

250.03

291.7

333.37

80

109.38

145.85

182.31

218.77

255.23

291.7

90

97.23

129.64

162.05

194.46

226.88

259.29

100

87.51

116.58

145.85

175.02

204.19

233.36

300

MARLING TABLES.

Table III., showing the number of rectangular spaces, of various dimensions,
in an acre of land.

Rectan-

Rectan-

Yards.

Sq. yds.

gular
Spaces.

Yards.

Sq. yds.

gular
Spaces.

15x15

—225

22

12x10

=120

40

15x14

=210

23

12x 9

=108

44

15x13

195

25

12x 8

96

50

15x12

180

27

12x 7

84

57

15x11

165

29

12x 0

72

67

15x10

150

32

11x11

121

40

15x 9

135

36

11x10

110

44

15x 8

120

40

llx 9

99

48

14x14

196

24

llx 8

88

54

14x13

182

26

llx 7

77

62

14x12

168

29

llx 6

66

73

14x11

154

31

10x10

100

48

14x10

140

34

lOx 9

90

53

14x 9

126

38

lOx 8

80

60

14x 8

112

43

lOx 7

70

69

14x 7

98

49

lOx 6

60

80

13x13

169

28

lOx 5

50

96

13x12

156

31

9x 9

81

59

13x11

143

84

9x 8

72

67

13x10

130

37

9x 7

63

76

13x 9

117

41

8x 8

64

75

13x 8

104

46

8x 7

56

86

13x 7

91

53

7x 7

49

98

12x12

144

33

7x 6

42

114

12x11

132

36

6x 6

36

133

It is scarcely necessary to direct the application of these tables
to practical operations; and therefore a single example only will
be offered. Suppose a farmer's marl contains about 40 per cent,
of carbonate of lime, and he wishes to give 1 per cent, to his de-
signed tilled depth of 5 inches. He takes the number 40 per cent,
in the first column of Table II., and passes thence in the same
horizontal line across the table until reaching the column headed
^' 5 inches.'' The number at the intersectiom is 364.62, the num-
ber of bushels of marl required. Next, to apportion this quantity
to the acre. The heaps he can most conveniently make, we will
suppose, will be 8 bushels. Dividing 364.62 by eight, gives about
45 J heaps required for the acre. Then referring to Table III., for
that number of spaces, or the nearest to that number, in an aero,
it is seen that the distances of

14 X 8 yards, will make 43 heaps.

13 X 8 " « 46 «

11 X 10 " " 44 "

Either of these quantities would be suitable enough ; and the
farmer would choose the distances which will best suit his width

MARLING ESTIMATES. 301

of ploughing. If desiring more perfect exactness, it could be easily
obtained by adding to or deducting from one of the dimensions the
necessary fraction of a yard.

Heaped bushels of loose marl, as measured separately, do not
vary much from the same number of even bushels, as compressed
in a cart body, by its own weight, and by the travel to tho field.
I find reference to bushels more convenient than to cubic feet. But
if preferred, the same desired results may be reached by using
Table I., and cubic feet as the measure instead of bushels.

The measuring of marl, in a half-bushel measure, for the purpose
of determining larger quantities, is but a rough and uncertain
method, which is only to be relied on when the average is taken
of many such trials. The irregularity of the lumps of marl, when
first dug, and the uncertainty of the degree of heaping of the
measure, may make even the same kind and condition of marl
appear to vary in quantity and weight, by 6 or 8 pounds in the
bushel. Besides other smaller trials, at other times, I made the
following measurements and weighings of a single load of marl, of
which the report may be of use for comparison : —

A load of marl, just dug, was thrown into the cart, as usual, by
shovols. The heaping of the load rose 7 inches, in the middle,
above the top of the cart body. (Lumpy and moist marl may be
heaped much higher than dry and pulverized.) This was about
the ordinary degree of heaping, when the roads were in the firmest
state. The load was drawn to my barn, 2000 yards of the route to
the field, and there measured by the half-bushel, heaped, and each
separate measure weighed. The weights varied from 49 to 56^
lbs. of the 39 half-bushel measures (19 i^ bushels) which the load
filled. The whole load weighed 2050 lbs., and the average weight
of the heaped bushel was 105.16 lbs. This marl was of the kind I
have altogether used at Marlbourne [to 1850] — compact clayey
marl, partly in lumps, moist naturally in its bed, but free from any
other water.

The inside dimensions of this two-mule cart body were these :
Average of length, inches, 60.87
" width, ^< 40

- " depth, " 15.16;

which make 21.36 cubic feet, or 17.12 even bushels of capacity.
(A bushel contains 2150.6 cubic inches.) But, it should be ob'
served, that the compression of the marl by its own weight, as
thrown into the cart, and still more by the settling during the tra-
vel to the field, permits and causes more bushels of marl (if pre-
viously measured) to be put into the body than would be indicated
by its cubic capacity. Thus, into the cart described above, at an-
other time, the marl was put in at the pit by a half-bushel measure,
heaped as usual — and which heaping certainly added as much as
26

302 MARLING ESTIMATES.

20 per cent, to the even measure. Yet 16 bushels (the measure
being thus heaped), were required to fill the cart even. (If thrown
in, as usual, by shovels, still more marl would have been put into
the same space, by its falling more heavily from the shovels than
from the half-bushel.) Upon this even filling of the cart (the 16
heaped bushels), more marl was added, to the amount of 5 bushels
of like heaping measurement, making 21 heaped bushels in all.
This raised the heaping of the cart higher than usual, though not
too much to be carried without waste. After being driven to the
field, rather more than IJ miles, the then heaping part of the load
alone was carefully taken ofi", and measured by even half-bushels;
but each filling being pressed into the measure moderately, which
was supposed to give a degree of compactness equal to the remain-
ing lower part of the load, caused by its weight and the travel.
This quantity made 3j of such even bushels; the diff'erence be-
tween which and the 5 heaped bushels put on in heaping at the
pit, was owing to the settling of the whole load by its weight and
the travel.

The remaining even and compressed filling of the cart body, by
cubic measurement of its capacity, as stated above, was (21.36
cubic feet, or) 17.12 even bushels. Add to this the 3 J even and
compressed bushels of the heaping (after its being settled by the
travel), and the quantity of the whole load is (17.12 -f 3.50=) 20.62
compressed and even bushels, equal to 21, loose and heaped, as
measured at the loading. Therefore it may be considered that a
heaped bushel of loose and moist marl is about equal, when com-
pressed, to the same measure even full.

From all these and other trials and observations, combined and
compared, I consider the following quantities as sufficiently close
approximations to the truth : —

A heaped bushel of this and similar marl, loose, as dug, weighg
105.16 lbs.

An even bushel, compressed, weighs about the same.

The load of a proper two-mule cart, for roads in good order and
over firm land not varying much from level, is 18 to 19 heaped
bushels— or 1900 to 2000 lbs.

Weight of a cubic foot of this marl, in the bed, is 120 i lbs.
(determined by trial of a smaller measured solid). By two differ-
ent trials, of pits measured by their cubic dimensions in the bed,
one of 1052 cubic feet yielded 1103 heaped bushels of marl, as dug,
and measured by the estimated cart-loads ; and the other, of 1475
cubic feet in the bed, yielded 1675 heaped bushels. These esti-
mates would respectively make the cubic foot weigh about 111 and
119 lbs. Of course these were not exact measurements, either in
the bed, of feet, or in the carts, of bushels.

10 cubic feet of marl, measured in the cart body, and as com-

PROPER PROCEDURE FOR MARLING. 303^

pact as made by its own pressure and the travel, are equal to 8.03
(say 8) even bushels, in the same state of compactness ; and may
be taken as equal to the same, number (8) of heaped bushels, loose
as when dag.

In marls of equal degrees of moisture, the weight will be greater
in proportion to the quantity of silicious sand in each; and, in a
less degree, also to the soundness and compactness of any shells
contained. In marls similar in these respects, of course the weight
will be in proportion to the wetness. The lightest marl I ever
worked, which was as dry as any earth could naturally be, did not
weigh less than 100 lbs. to the heaped bushel.

Some or all the foregoing suggestions of facilities and expedients,
or perhaps some better plans, might perhaps occur to most persons
before they are long engaged in marling. Still these directions
may help to smooth away some of the obstructions in the way of
the inexperienced ; and they will not be entirely useless, if they
can serve to prevent even small losses of time and labour.

It is impossible to carry on marling to advantage, or with any-
thing like economy, unless it is made a regular business, to be con-
tinued throughout the year, or a specified portion of it, by a labour-
ing force devoted to that purpose, and not allowed to be withdrawn
for any other. Instead of proceeding on this plan, most persons
who have begun to marl, attempt it in the short intervals of leisure
afforded between their different farming operations — and without
lessening, for this purpose, the extent of their usual cultivation.
Let us suppose that preparations have been made for such an at-
tempt, and on the first opportunity, a farmer commences marling
with zeal and spirit. Every new labour, however, is attended by
causes of difficulty and delay ; and a full share of these will be
found in the first few days of marling. The road is soft for want
of previous use, and, if the least wet, soon becomes miry. The
horses, unaccustomed to carting, balk at the hills, or carry only half
loads. Other difficulties occur from the awkwardness of the labour-
ers, and the inexperience of their master — and still more from the
usual unwillingness of the overseer to devote any labour to improve-
ments which are not expected to add to the crop of that year.
Before matters can get straight, the leisure time is at an end. The
work is stopped, and the road and pit are left to get out of order,
before making another attempt some six months after, when all the
same vexatious difficulties are again to be encountered. It is there-
fore not at all surprising that many zealous beginners have been
discouraged by the bad management of their first operations ; and
have abandoned all effort to marl, until after years of delay, and
when again induced to resume, by the success and profit of others
who had not limited their marling labours to leisure times onl3\

If one horse or mule, only, is employed in drawing marl through-

304 SEARCHING FOR MARL.

out the year, at the moderate allowance of 200 working daySj
and 100 bushels carried out for each day, the j^ar's work will
amount to 20,000 bushels ; or enough for the first dressing of 80
acres, at 250 bushels. This alone would be creating a great value,
and obtaining a great profit upon the outlay of expense. But, be-
sides, this operation would allow the profitable employment of any
amount of additional and available force. When, at any time,
other teams and labourers could be spared to assist, even if but for
a day or two, everything would be ready for them to go immedi-
ately to work. The pit is well drained, the road is firm, the bridges
in good order, and the ground for the marl marked off and ready
to receive the loads. In this manner, much work may be obtained
in the course of the year, from teams which would otherwise be
idle, and labourers whose other employment would be but of little
importance. Also the spreading of marl on the field is a job that
will be always ready to occupy spare labour (unless the marl is
clayey and also very wet) ; and the removing of earth to uncover
marl may be done when rain, snow, or severe freezing weather has
rendered the earth unfit for almost every other kind of work.

CHAPTEB, XXVir.

DIRECTIONS FOR THE SEARCHING FOR AND TESTING OF MARL.

In the order of time and of operations, the searching for marl,
when required for any one locality, must precede the labours di-
rected or described in the foregoing chapter. Nevertheless, the
reverse order will be better for the clear understanding of directions
by those persons who are without any experience in this business. To
know how best to search for marl, it is essential to know the gene-
ral position, and other characters of the beds ; and the necessary
lights on these points were given in the preceding chapter as the
most suitable place.

It is not only on farms, or in larger spaces, where no marl has
been seen, that the search for it may be necessary. On large farms
where it is most abundant, and easily accessible, in some places, it
is usually very important to trace the bed to some other place,
where the working will be more useful or convenient. The being
thus enabled to bring the excavations a few hundred yards nearer
to the fields may save twice as many hundred dollars inihe expense
of carting the marl within one or two years.

The farmer who has seen (and still better if he has worked)
jnarl in some one spot of his land, or his neighbourhood, has thereby

SEARCHING FOR MARL. dUO

obtained tlie best possible indications of the probable existence of
the same bed in a more desirable situation. As the beds usually
lie nearly horizontal, and are continuous for considerable distances,
the search should >e extended upon nearly the same level. . Natural
exposures may have been made by the courses of rivers or smaller
streams — or artificial, by the digging of ditches, wells, or other
excavations. If none of these serve to expose marl to view, the
next resort will be to boring. And in using the auger, the same
rule should be pursued of being guided by the supposed level of
the bed sought. Of course, any nearly horizontal lower bed will
have the least covering of upper earth where the surface is most de-
pressed. Thus, under swamps, or in deep bottoms or ravines, a hidden
bed of marl may be expected to be reached with less depth of boring
than on the higher land. But it will not do to rely upon borings
in these lowest depressions only. For in many cases, the marl
itself, or the upper part of the bed, has been washed away and re-
moved by the ancient action of running water, and the cavity sub-
sequently filled by other washings of earth, forming the present
surface soil and lower layers. Therefore, besides boring in the
lowest ground, the nearest rise of the adjacent slope of high land
should be tried. There the marl would have been left, even though
removed in the former lower channel of the ancient strong current
of water.

If marl reaches the surface, or is cut into anywhere by the wash-
ing of rapid streams, it may probably be found by examining the
deepest parts of these cuttings. Any of the smallest particles of
shells found in the lower part of the course of the stream will
clearly indicate that the water has cut into marl somewhere above;
and which place may be found by carefully examining the bed of
the stream above.

The auger most convenient for the ordinary searching for marl
is a very simple and cheap implement. It is made by welding a
straight cylindrical iron rod, five-eighths of an inch in diameter,
to the stem of a common screw auger of about one and a half
inches bore. If the auger has been so much worn in use as a car-
penter's tool, as to be unfit for that work, it will serve well enough
for boring in earth. A cross-piece for a handle, also of iron, and
14 inches long, should be fitted to slide along the stem (which
passes through a hole in the handle), and small indentations are
made, two feet apart, on the stem, at which the handle is fixed, at
any desired height, by a small thumb-screw, passing through one
side of the handle, and the point pressing into the indentation on
the stem. The lowest indentation should be 4 feet from the lower
end of tli^ auger, and the others at every 2 feet above. An
auger of 12 feet length will serve for all ordinary operations,
and is not too unhandy in use. But, it will be more convenient,
26*

806r BORING FOR MARL.

if raucli boring is to be done, to have two augers, of equal bore
(or the short one something the Larger), one of 8 feet length, and
the other 14. The shorter will be used first, and the longer only
when more than the depth of 8 feet is required. The auger is not
only useful to find the upper surface of the bed of marl, but also
to pierce the bed deeply enough to know whether it is thick and
rich enough to be worth the labour of uncovering and excavating.
Not more than about 6 inches depth should be bored at one time,
when the auger should be drawn up, and the cutting part cleared
of the adhering earth. If more boring is done at once than the
auger can lift completely, the bored hole is soon obstructed by
loose earth, and the design of the boring is impeded by the greater
haste of the labour. •

It is seldom that the shorter length of 8 feet will not be enough
for these uses of a marl auger; and the greater length of 12, or
at most 14 feet, will be ample. But, if for peculiar circumstances,
greater depth is required, additional pieces, of 4 feet each, may be
attached to and so lengthen the stem of the auger. The working
of so long an auger is excessively inconvenient, when it has to be
drawn up so frequently.

For the suggestion of this very useful tool, I was indebted to
Dr. William J. Cocke, who first introduced it ; and who, by its aid,
was enabled to find and to use extensively a very valuable bed of
marl under the low and level surface of his land (on Blackwater,
in Sussex), where its presence had not been reached or suspected
before.

When it is desired to use an auger longer than 14 feet, by at-
taching one or more extra joints, the great inconvenience of lifting
and returning the auger may be much lessened by a simple con-
trivance introduced by Mr. Williams Carter, of Hanover. This is
to have a bench of narrow and thin plank, 7 or 8 feet long, with
legs of 8 or 10 feet. A hole large enough for the auger to turn
in freely is in the middle of the bench. As soon as it is necessary
to attach another piece to the stem of the auger, the bench is set
over the boring, with the hole immediately above, through which
the stem is passed. Thus, when the auger is lifted, it is supported
in its perpendicular position by the bench above.

Such means as these, imperfect as they are, will be found more
convenient and effective in use, and much cheaper, than the heavy
and complicated augers used to search for coal.

When I first began to apply marl, in Prince George county, it had
attracted so little observation, even as a matter of curiosity or singu-
larity, that the deposit was supposed by the few observers to be
limited to the few places where it was both exposed an#also mani-
fest to the eye. These places were indeed very few in lower Vir-
ginia. For not only was the natural exposure of a section of the

POSITION OF MARL BEDS. 307

bed required, but also that the fossil shells should be sufficiently
preserved to be recognised as such at a glance. The most nume-
rous, most extensive, and also the richest beds, exposed to the eye,
in some of the steep and broken banks of the rivers, and which are.
now known to the most ignorant labourer as marl, were then not
distinguished from other earth, because the shelly matter was so
reduced as not to be obvious to view.

But as soon as the value of these beds was made known, disco-
veries or observations of their presence and accessibility were rapidly
extended. And in advance of all scientific instruction (from which
the general extension of any such formations might have been in-
ferred), marl had been found on thousands of farms, where its pre-
sence had not been known or thought of, previous to my earliest
publication on this subject. Even in Prince George, and after the
highest interest had been excited on this subject, for some years
the only known exposures of marl were in either the cliffs, or the
neighbouring sloping borders of James River, and in the ravines
of the hilly lands of some streams emptying therein. Since, besides
other places, under all or nearly all the level swampy borders of
the Blackwater and its many branches, marl has been found, at no
great depth, though concealed from view ; and numerous extensive
excavations have been made, and for great improvements. New
discoveries of marl are still continually made in localities where it
was not before known. There can be little question of the general
fact that marl underlies nearly all the lands between the sea coast
and the falls of the rivers, and stretching from Maryland to Florida ;
and increasing in thickness, and generally in richness also, as pro-
ceeding southward. In Virginia, the workable thickness of marl
is not often more than 12 feet ; and if in some cases as much as
25 feet, it is much oftener less than 8 feet. In South Carolina,
I ascertained the extensive bed of very rich marl to be more than
300 feet in thickness.

But generally extended as are the marl deposits through lower
Virginia, the overlying earth is most generally too thick for the
economical working of the marl below. Under most lands, the
marl is more than thirty feet below the surface ; and even if reached
by digging, would be covered by spring-water, so as greatly to in-
crease the difficulty and expense of obtaining it from such depths.
Will these obstacles always debar the proprietors from the benefit
of this treasure, through more than half the great region under
which it lies, now useless and concealed? I think not. Though
it would be ridiculous now to propose such undertakings, it will
at some future time be found profitable to descend to still greater
depths for good marl ; and shafts will be sunk, and the water and
the marl will both be drawn up by machinery worked by horse-
power or steam engines, and the excavations conducted in the same

508 DEEP-LYING MARL.

manner as is now done in coal mines. "When sucli means shall bo
resorted to, it is probable that there will be but a small proportion
of all the great tide-water region (or the region lying eastward of
the granite range), in which marl may not be found sufficiently
accessible for profitable use. For example : from a mile south of
Petersburg, along the line of the railway to the Roanoke, no marl
had been found either by the excavations for the road, or in tho
much deeper wells dug long before in the vicinity of the route.
The well for the water-station nine miles from Petersburg did not
at all times supply enough water for the engines, and it was deter-
mined to dig one deep enough for that purpose. Disregarding the
small veins of water usually reached at less than 20 feet, the
digging was sunk to 50 feet, when marl was reached. Its quality
at top was rather poor ; but it became more and more rich, as well
as of firmer consistence (though never very hard), until the well
had been sunk to 80 feet, without reaching the bottom of the
marl, or finding any other vein of water. The lower part of this
marl was from eighty to ninety per cent, of carbonate of lime, as I
found by several analyses. It would have served to make good
lime, by burning, for cement or for manure, to be transported to
a distance on the railway ; besides being of more value to be used
unprepared to enrich the nearer land. Though covered by fifty
feet of earth, and the excavation impeded by the water from above,
this marl might have been profitably raised eighty feet, or as much
lower as the bed may extend. And so firm was its texture, that
the excavation might have been safely enlarged gradually as it was
deepened, as is done in the chalk-pits of England, so that the
digging should form a hollow cone, communicating from its apex
by the narrower cylindrical well through the fifty feet of earth
above to the surface. Thus, though the earth might have been
twice the thickness of the marl below, the greater diameter of ex-
cavation in the latter would have furnished much the greater quan-
tity of contents. Of this most valuable deposit, found in a region
before supposed destitute, and where its transportation to a long
line of destitute land was so convenient, no use has been made,
except of the quantity necessarily drawn up in digging this well.
And this means for enriching the undertaker, and fertilizing a vast
extent of surface of acid and poor land, will probably remain totally
neglected for the next fifty years. It is most probable that this
same thick and rich body of marl may be found at many miles'
distance on the line of railroad, and indeed wherever the surface
is in the same position relative to the granite range. (1842.)

After marl has been found, whether by natural exposure or by
boring, it may still be difficult to distinguish it by the eye. If
fossil sea-shells are intermixed, and enough preserved in form to be
distinguishable, that is certain proof that the object sought has

MARLS NOT DISTINGUISHABLE BY SIGHT. 809

been found. But sometimes, and more usually in the richest marls,
the shells are so reduced as to be scarcely (if at all) distinguishable,
and the mass may appear to the eye either as a barren sand or as
barren clay sub-soil, according to its mechanical texture, of no
worth or interest whatever. The touch of muriatic, or other strong
atid, to the earth, jSirst moistened by water, is the only sure test.
If there is shelly matter (or carbonate of lime) present, the acid
will produce immediate effervescence and discharge of carbonic acid
gas. If there is no such action, the earth is not calcareous, and
of no value as marl (or for calxing'), whatever it may contain of
other fertilizing ingredients.

More than a hundred species of sea-shells are found in the
beds of marl which I have worked. Generally the shells,
though very fragile, are entire, though much broken by the dig-
ging and after-operations. The white shells are rapidly reduced,
after being mixed with an acid soil ; but some gray kinds, as
the scallop (^pecien) and the oyster, are so hard as to be very long
before they can act as manure. Some beds, and they are gene-
rally the richest, have scarcely any whole shells, but are formed
principally of small broken fragments. Of course the value
of marl as a manure depends in some measure on which kinds
of shells are most numerous, and their state of division, as
well as upon the total amount of the calcareous earth contained.
The last is, however, by far the most important criterion of
value. The most experienced eye may be much deceived in the
strength of marl ; and "still more gross and dangerous errors
would be made by an inexperienced marler. The strength of a
body of marl often changes materially in sinking a foot in depth —
although the same changes may be expected to occur very regu-
larly, in every pit sunk through the same bed. The annexed
figure will serve better to illustrate both these changes in perpen-
dicular extension in a marl-bed, .and the regularity of quality in
horizontal extension.

6Jf

. .-/ r'
3

- — & ., , ■

.

--

3

d

'

<9

6

Such as this is no uncommon character of a bed of marl, and
such I have worked, and could recognise the identity of the
several layers, by their appearance, in different diggings, half a
mile or more apart. Thus, suppose the two ends of the section

•10 APPEARANCE AND TESTING OF MARL.

to be at such considerable distance. The upper layer, a (say,
for example, finely-rubbed-down fragments of shells, making 55
per cent, of the layer), may be 6 feet thick at one part, and only 1
foot or less at the other. The next layer, h (indurated or stony, 85
per cent, of carbonate of lime), may vary at the same two distant
places from 1 foot to 3. The next, c (sandy and fine, 20 per
cent.), is 4 feet in one digging, and runs out to nothing before
reaching the other. The next, d (firm, with entire shells, 40 per
cent.), is 7 feet in the one and but 3 in the other place. Now it
would require a careful analysis of each of these layers of diiferent
qualities, and observation of their comparative thickness, to know
the average strength of the whole section of marl at one excava-
tion. But these same observations would usually serve for estimat-
ing nearly enough the averages of the like layers whenever they
were found and identified, by allowing for the changes in thickness
of each layer.

Whoever uses marl ought to know how to analyze it, which
a little care will enable any one to do with sufficient accuracy.
The method described, at page 56, for ascertaining the propor-
tions of calcareous earth in soils, will of course serve for the
same purpose with marl. But as more particular and minute
directions may be necessary for many persons who will use this
manure, and who ought to be able to judge of its value, such
directions will be here given, and which any one can follow,
by merely applying sufficient attention and care. To perform
this process will require no other chemical tests than muriatic
acid and carbonate of potash, and no apparatus, except correct
scales and weights, a glass funnel, and some blotting or very porous
printing paper — all of which may be bought at any apothecary's
shop.

Directions for analyzing Marl hy solution and precipitation.

1st. Take a lump of marl, fossil shells, &c., large enough
to furnish a fair sample of the particular body under considera-
tion— dry it perfectly near the fire — pound the whole to a coarse
powder (in a metal mortar), and mix the whole together.
Take from the mixture a small sample, which reduce to a finely-
divided state, and weigh of it a certain portion, say 50 grains, for
trial.

2d. To this known quantity, in a glass, pour slowly and at dif-
ferent times muriatic acid diluted with three or four times its bulk
of water (^ny except lime-stone, or hard water.) The acid will
dissolve all the lime in the calcareous earth, and let loose the car-
bonic acid, with which it was previously combined, in the form of
gas, or air, which causes the effervescence, which so plainly marks

ANALYZING OF MARL. 811

the progress of such solution. The addition of the muriatic acid
must be continued as long as it produces effervescence ; and but
very little after that effect has ceased. The mixture should be
well and often stirred, and should have enough excess of acid to be
sour after standing thirty or forty minutes. (So much of the acid
as the lime combines with loses its sour taste, as well as its other
peculiar qualities.)

The mixture now consists of: 1, the lime combined chemically
with muriatic acid, forming muriate of lime, which is a salt, and
which is dissolved in the water ; 2, a small excess of muriatic acid
mixed with the fluid ; and 3, the sand, clay, and any other insolu-
ble parts of the sample of marl. To separate the solid from the
fluid and soluble parts is the next step required.

3d. Take a piece of filtering or blotting paper, about six or eight
inches square (some spongy and unsized newspapers serve well),
fold it so as to fit within a glass funnel, which will act better if its
inner surface is fluted. Pour water first into the filter, so as to see
whether it is free from any hole or defect ) if the filtering paper
operates well, throw out the water, and pour into it the whole
mixture. The fluid will slowly pass through into a glass under the
funnel, leaving on the filter all the solid parts, on which water must
be poured once or twice, so as to wash out and convey to the solu-
tion every remaining particle of the dissolved lime.

4th. The solid matter left, after being thus washed, must be
taken out of the funnel on the paper, and carefully and thoroughly
dried — then scraped off the paper and weighed. The weight, say
27 grains, being deducted from the original quantity, 50, would
make the part dissolved (50 — 11 =23) 46 per cent, of the whole.
And such may be taken as very nearly the proportion of calcareous
earth (or carbonate of lime) in the earth examined. But as there
will necessarily be some loss in the process, and every grain taken
from the solid parts appears in the result as a grain added to the
carbonate of lime, it will be right in such partial trials to allow
about two per cent, for loss, which allowance will reduce the fore-
going statement to 44 per cent, of carbonate of lime.

5th. But it is not necessary to rely altogether on the estimate
obtained by subtraction, as it may be proved by comparison with
the next step of the process. Into the solution (and the washings)
which passed through the filter, p^||^ gradually a solution of car-
honate of potash. The first effect^P the alkaline substance, thus
added, will be to take up any excess of muriatic acid in the fluid —
and next, to precipitate the lime (now converted again to carbonate
of lime), in a thick curd-like form. When the precipitation is
ended, and the fluid retains a strong taste of the carbonate of
potash (showing it to remain in excess), the whole must be poured
on another filtering paper, and (as before) the solid matter left

312 ANALYZING OF MABL. '

tliereon repeatedly washed by pouring on water, then dried, scraped
oiF, and weighed. This will be the actual proportion of the calca-
reous part of the sample, except, perhaps, a loss of one or two
grains in the hundred. The loss, therefore, in this part of the pro-
cess apparently lessens, as the loss in the earlier part increases the
statement of the strength of the manure. The whole may be sup-
posed to stand then :

27 grains of sand and clay ")

21 " of carbonate of lime t = 50.

2 " of loss )

If the loss be divided between the carbonate of lime and the other
worthless parts of the manure, it will make the proportion 28 and
22, which will be probably near the actual proportions.

The foregoing method is not the most exact, but is sufficiently so
for practical use. All the errors to which it is liable will not much
affect the reported result — unless magnesia is present, and that is
not often in manures of this nature. I have never found carbo-
nate of magnesia in any of the deposits of fossil shells in Virginia,
though it was in many cases sought for.* If, however, any consi-
derable proportion of carbonate of magnesia should ever be present
in marl tried by the foregoing method, it may be suspected by the
effervescence being very slow compared to that of carbonate of
lime alone ; and the proportions of these two earths may be ascer-
tained as follows : The magnesia as well as the lime would be dis-
solved by the muriatic acid (applied as above directed), but the
magnesia would not be precipitated with the carbonate of lime, but
would remain dissolved in the alkaline solution, last separated by
filtering. If this liquor is poured into a Florence flask and boiled
for a quarter of an hour, the carbonate of magnesia will fall to the
bottom, and may then be separated by filtering and washing, and
its quantity ascertained by being dried and weighed. — (Davy.)
This part of the process may be added to the foregoing, but it will
very rarely be required.

If desired, the proportions of sand and clay (besides the calcare-
ous parts of each) may be ascertained with enough truth for prac-
tical purposes, by stirring well the remaining solid matter in a

^- Carbonate of magnesia is known to me only in one case. This is of a
peculiar compound of carbonates^^ lime and magnesia with other common
earths, found on Bear Creek IsH^in Hanover county, above the falls of
Pamimkey. I have seen it only in a specimen sent to me fifteen years ago,
and of which analyses were made both by Prof. W. B. Rogers and myself,
in difiFercnt modes, with like results. I presume this earth must have been
found in very small quantity, as I have never heard of its being used as
manure, nor indeed anything else about it.

Prof. C. U. Shepherd reports magnesia found by him in some of the rich
eocene marls of South Carolina. I had before sought for it in vain, in many
other specimens of the same general kind of marl.

ANALYZING OP MARL. 313

glass of water, and, after letting it stand a minute, for the sand to
subside, pouring ofi" the fluid, with the lighter and still floating clay,
into another glass. The sand will he left, and the clay will be
poured off with the water ; and each may be collected on filtering
paper, dried, and weighed separately.

The proportion of carbonate of lime in marl may also be conve-
niently and correctly determined by the diminution of weight from
the escape of the carbonic acid ; the quantity of which is always
in an invariable proportion to the lime with which it is combined.
For this purpose, weigh (in a thin and open-mouth vial) a certain
quantity (say 200 grains) of muriatic acid. Then of well dried
and powdered marl, weigh half as much (100 grains), and then add
the weighed marl, very slowly and gradually, to the acid. After
all effervescence has ceased, the whole will fall short of the original
weights (300 grains), by that of the carbonic acid evolved. This
bears the fixed proportion (very nearly) to the carbonate of lime,
of 45 parts in the 100. Therefore for every 4.5 grains weight
lost, estimate 10 grains of carbonate of lime in the marl tried. —
(Davy.) '

For want of attention to the only safe guide, the chemical analy-
sis of marl, gross errors are often committed, and losses continually
sustained. By relying on the eye only, I have known marl, or
rather a calcareous sand, to be rejected as worthless, and thrown
off at considerable cost of labour, to uncover worse marl below, in
which whole shells were visible ; and on the contrary, earth has
been taken for marl, and used as such, which had no calcareous
ingredient whatever. The best marls for profitable use are gene-
rally such as show the fewest whole shells, or even large fragments,
and would be passed by unnoticed in some cases, or considered
only as barren sand, or equally worthless clay. But even if such
mistakes as these are avoided, every farmer using marl, without
analyzing specimens frequently and accurately, will incur much loss
by applying it in quantities either too great or too small.

Distant transportation of Ilarl.

An interesting question respecting the expense of this improve-
ment is, to what distance from the pit may marl be profitably
carried? If the amount of labour necessary to carry it half
a mile is known, it is easy to caleiialate how much more will be
required for two or three miles. The cost of teams and drivers is
in proportion to the distance travelled^ but the pit and field labours
are not affected by that circumstance. At present, when so much
poor land, abundantly supplied with fossil shells, may be bought at
from two dollars to four dollars the acre, perhaps a farmer had bet-
ter buy and marl a new fiirm, than to move marl even three miles
27

814 DISTANT TRANSPORTATION OF MARL.

to his land in possession.* But this would be merely declining one
considerable profit, for the purpose of taking another much greater.
Whenever the value of marl shall be properly understood, and
our lands are priced according to their improvement, or their capa-
bility of being improved from that source, as must be the case here-
after, then this choice of advantages will no longer be ojBfered.
Then rich marl will be profitably carted eight or more miles from the
pits, and perhaps conveyed by water as far as it may be needed. A
bushel of such marl as the bed on James river, described {lage 144,
containing 62 per cent, of carbonate of lime, is as rich in calca-
reous earth alone, as a bushel of slaked lime,, will be after it
becomes carbonated; and the greater weight of the first is a less dis-
advantage for water carriage, than the price of the latter. Many
marls, in other places, are much richer than this, and also dry, and
easy to work. Farmers on James river, who have used lime as
manure to great extent and advantage, might more cheaply have
moved rich marl forty miles by water, as it would cost nothing but
the labour of digging and transportation. (1832.)

Within the short time that has elapsed since the first publica-
tion of the foregoing passages in the previous edition of this essay,
the transportation of marl by water carriage has been commenced
on James river, and has been carried on with more facility and at
less expense than was anticipated. The farmers who may profit by
this new mode of using marl will be indebted to the enterprise of
C. H. Minge, Esq., of Charles City, for having made the first full
and satisfactory experiment of the business on a large scale.
(1835.) I induced this gentleman to undertake this operation, for
improving his farm in Charles City county (now known as Sher-
wood Forest, and the property and residence of President Tyler),
not only by advice, but by ofi"ering to him the gratuitous use of my
marl on Coggins Point. His operations were continued through
two years. His example was subsequently followed by some other
farmers to less extent, and at much greater cost, as they hired the
freighting, though obtaining the marl from me, in the bed, without

* This statement of prices, though correct when first published (in 1832),
IS no longer so. Some little land may yet be so low ; but, in general, the
prices of lands having marl have already advanced from 60 to 100 per cent,
■yvithin fifteen years (1842). The lowest of the above-named prices was much
above the former minimum rate. The various tracts of land in James City
county, belonging to Mrs. Paradise's large estate, when sold some 12 or 14
years ago, brought prices that averaged only about $1.25 the acre. Most
of the lands were poor, but easily improvable, and all having plenty of rich
marl. One of the tracts of that description, of 800 acres, was bought at
75 cents the acre ; and after being held for three or four years, without
being in any respect improved, was re-sold by the purchaser for $2.50 the
acre. "Where marl has been actually applied, the increased intrinsic or
productive value of the land always considerably exceeds the increased
market price, even though the latter may be already doubled or tripled.

WATER-BOMTE MAM.? " - g^g

charge. Since, the business has greatly increased, and is now car-
ried on by many flat-bottomed vessels (or lighters, decked and
rigged), from other places on James river, as a regular and con-
tinuous business. But still the business is badly conducted in
general, and therefore is much more costly than it would be under
better and proper direction. Farmers are averse to being engaged
in the management of vessels, or any other business away from
their farms, and therefore they have always preferred to buy the
marl from vessels, even at higher prices, rather than to have it dug
by their own labourers and transported in their own vessels. And
this division of labour would be right in all respects, if the owners
of the river lighters were better managers of their business, and
their han.ds were industrious and sober. For rich marl thus ob-
tained and transported, the prices at the purchasers' landings have
usually been from 4 to 5 cents the heaped bushel. And at these
high prices, the lazy and worthless and ill provided navigators
have rarely realized any profit. The highest price charged for marl,
in beds on the river banks, is a half cent the bushel. Under ex-
isting circumstances, the cheapest and best mode of obtaining
water-borne marl is for the farmer to also carry on the digging and
the navigating. And if the several operations were properly con-
ducted, the entire expense of water-borne marl, say 10 to 30 miles,
will rarely exceed 3 cents the bushel when landed, and under
favourable circumstances may fall short of 2 cents. Collier H.
Minge, Esq., and Gen. Corbin Braxton, of King William county,
who have carried on this business extensively, and for years in sue.
cession, for marling their own farms, have furnished me with careful
and detailed estimates of their expenses, which have been published
at length in the Farmer's Register (p. 567, vol. i., and p. 691, vol.
viii.). According to the estimate of Mr. Minge, the entire cost of
thus procuring marl, carried 15 miles on the broad water of James
river, amounted to less than 2 cents the heaped bushel when landed.
And Gen. Braxton's total expense, the transportion being for eight
miles on the narrow and smooth Pamunkey, was but little more
than half a cent the bushel, placed at his landing. No charge was
made for the marl in either case, but every other charge or expense
was included. The labour and difficulties on James river, both
of uncovering and digging the marl (at Coggins Point) and un-
loading (on a shallow creek) were unusually great ; and on the
Pamunkey these labours were very light. A vessel and also a
mode of loading, which would be safe in strong winds, were neces-
sary on James river ; while no such danger had to be feared, or
wa^ guarded against, on the well-sheltered Pamunkey river. So
much of the business, in both these cases, as was conducted from
home, necessarily was wanting of proper superintendence ; and, no
doubt, both of these undertakings suffered for that important de-

^W WATER-BORNE LIME.

ficiency, as in all cases wliere labour is on a small scale of opera*
tionSj and more especially when slave labour is employed.*

Another source for obtaining calcareous manures has been opened
to the farmers of lower Virginia, which they think cheaper than either
transporting marl or burning shells, and they are availing themselves
of it to great -extent. This is northern stone-lime, which is brought
in bulk, ready slaked, and sold by the vessel-load at prices varying
from 8 to 10 cents the bushel. Slaked lime, even if pure, from
its extreme lightness, cannot be as much to the bushel as rich
marl contains of pure lime, even though the marl may have 30
per cent, of other earths. Therefore the lime js much the most
costly, as marl may be procured and transported at from 3 to 5
cents the bushel. Still, the lime is so much more readily obtained
in large quantities, and a fann can by that means be so much more
speedily covered, that the purchase of lime is often the more de-
sirable and also the more profitable operation of the two. (1842.)

In making this improvement, more than in any other business,
"time is money.'' Marling is usually effected by the farmer's
labour, whereas the expense of liming is mostly in the purchase.
By the use of water-barne marl, few farmers could dress a fourth
of their tillage field in a year, whereas by purchasing lime the
whole field might be limed, and the whole farm covered in one-
fourth of the time required for marling. If then the lime were
even thrice the cost of marl (for equal quantities of pure lime), it
would still be the cheapest mode of improvement, because yielding
its products in one-fourth of the time required for marling. The
difference of amount of net product in the first crop, between an
acre marled or limed, and another acre not so improved, would
usually pay the cost of marling or liming the acre. Therefore, ou
every acre cultivated by any farmer, and not marled or limed until

*^ Since 1843, the water-carriage of marl on James river has greatly in-
creased. About ten decked and rigged flat-bottomed vessels have generally
been employed in carrying marl from what may be considered one locality,
in the neighbourhood of my former residence, in Prince George county,
though on the close adjacent lands of three proprietors. Half a cent the
bushel is paid for the marl in its bed. For the labour and expense of
removing the overlay of earth, digging the marl and carrying it on board,
and conveying to distances from 15 to 40 miles, the carriers charge from
3^ to 4 cents — making the total cost at the buyer's landing place from 4 to
4| cents. A still larger business has been at the same time carried on in
bringing slaked stone-lime, in sea vessels, to James river, from the kilns
on the Schuylkill and Hudson, and elsewhere in the Northern States. This
lime has latterly been sold as low as 7 cents the bushel, usually, and in some
cases still lower. The principal demand for and use of both the water-
borne marl and lime is on the lands of Charles City county, where marl is
not found on any of the river lands, and in but few cases near to the
river. (1849.) The Schuylkill lime contains about 35 per cent, of mag-
nesia. The New- York lime contains much silex.

MARL ON RAIL-ROADS. 317

after making the crop, there is as miicli loss' of crop suffered by
the delay, as would have paid for making the improvement.

The objections to carrying marl unusual distances, admitted
above, apply merely to improvements proposed for field culture.
But it would be profitable, even under existing circumstances,
for rich marl to be carried 10 miles by land, or 200 miles by
water, for the purpose of being applied to gardens, or other land
kept under perpetual tillage, and receiving frequent and heavy
coverings of putrescent manure. In such cases, independent of
the direct benefit which the calcareous earth might afford to the
crops, its power of combining with putrescent matters, and pre-
venting their waste, would be of the utmost importance. If the
soil is acid, the making it calcareous will enable half the usual
supplies of manure to be more effective and durable than the whole
had been. There are other uses for marl, about dwelling-houses
and in towns, which should induce its being carried much farther
than mere agricultural purposes would warrant. I allude to the
use of calcareous earth in preserving putrescent matters, and
thereby promoting cleanliness and health ; which subject has been
already discussed.

Either lime or good marl may hereafter be profitably distributed
over a remote strip of poor land, by means of the railroad now
constructing from Petersburg to the Roanoke [1831]; provided
the proprietors do not imitate the over greedy policy of the legis-
lature of Virginia in imposing tolls on manures passing through
the James River canal. If there were no object whatever in view
but to draw the greatest possible income from tolls on canals and
roads, true policy would direct that all manures should pass from
town to country toll free. Every bushel of lime, marl, or gypsum
thus conveyed, would be the means of bringing back, in future
time, more than as much wheat or corn ; and there would be an
actual gain in tolls, besides the twenty-fold greater increase to the
wealth of individuals and the state.
* 27*

CHAPTER XXVIII.

ESTIMATES OP THE COST OF LABOUR APPLIED TO MARLING.

Before we can estimate with any precision the expense of im-
proving land by marling, it is necessary to fix the fair cost of every
kind of labour necessary for the purpose, and for a length of time
not less than one year. We very often hear guesses of how much
a day's labour of a man, a horse, or a wagon and team, may be
worth ] and all are wide of the truth, because they are made on
wrong premises, or no premises whatever. The only correct method
is to reduce every kind of labour to its elements, and to fix the
cost of every particular necessary to furnish it. This I shall at-
tempt ) and if my estimates are erroneous in any particular, other
persons better informed may easily correct my calculation in that
respect, and make the necessary allowance on the final amount.
Thus, even my mistakes in the grounds of these estimates will not
prevent true and useful results being derived from them.

The following estimates of the cost of labour were first prepared
in 1828, according to the actual prices of that year, and so appeared
in the three preceding editions of this essay. The lapse of time and
changes of average prices of some of the elements of cost required
correction of some of the particulars. The corrected estimates now
submitted are not (as before) of the actual prices of any one parti-
cular year, but the supposed average prices of a number of years,
to the end of the year 1846. In making the necessary corrections
for this purpose, some of the original charges were deemed too
high for the average statement desired, and others of larger amount
were too low. The difference is small (making less than 3 per cent,
of general increase), but has so far served to raise, on the whole, the
estimated costs of marling.

But no such estimates (even if at any one time correct in the
premises of prices assumed) can more than approach to accuracy
for any average of extended time, and still less for any particular
subsequent year, owing to the great and irregular fluctuations of
prices. Therefore, neither these nor any other estimates of costs
can be relied on to show the expense of labour always, or even
generally. But these may at least supply a convenient form and
rule for the true mode of estimating such values ) and every person
may easily change the particular charges as required to suit other
circumstances. Thus, even if other times and circumstances should
require changes of price of every element of labour, the form of

(318)

COST OF LABOUR — HANDS. 819

these estimates will still serve greatly to facilitate such alterations
and new calculations, and serve better to secure the accuracy of
the general results.*

Average prices of different elements of labour j applied to Marling
operations.
For a negro man —
Hire for the year, payable at the end . . . $50 00

Food — 102^ bushels of Indian corn, at 45 cents $8 77 J
Add 10 per cent, for loss in keeping 88

130 lbs. bacon, at 7 cents . . 9 10

Interest on $18.75^ for a year

Clothing-^6 yards of strong woollen cloth, at
50 cents ....

13 yards of cotton, for shirts and sum-
mer clothes, at 10

Woollen hat 50 cents, blanket $1.30,
each once in two years, is yearly

Shoes and mending ....

$18 75J
1 12J

$3 00

1 30

90

2 00

19 88

7 20

Taxes — State, 47 cents, county and poor, 80,
labour on public road, suppose two
days, 68 cents, ..... 1 95

For nursing when sick (exclusive of medical aid and
medicines), and share of expenses for quarters, fuel,
and sending to mill ...... 6 00

$85 03
Add to this amount, 10 per cent, for superintendence 8 50

Total expenses per yea-r, .... $93 53

* As stated above, these estimates were designed to suit the average
prices of a series of years preceding and including 1846. But since they
were prepared, owing to temporary causes, the prices of both hand and
mule labour have greatly advanced. Therefore, if any person designed
to begin a job of marling now, and had to incur for that purpose the recent
and still continuing high prices of mules and of hire of hands, the actual
advances on each of these particular expenses only should be added to the
general costs as here estimated. But, in fact, very few of our farmers
have to buy or to hire more than a small proportion of the force, if any, that
they apply to marling. Most landholders own enough, or nearly enough
labouring force, and had before kept it at less profitable employments, to
carry on marling in addition. This is known to be the case with nine in ten
of such operations. And so far as a farmer had been before the owner of
the labouring force he will devote to marling, and would have kept it,

820 COST OF LABOUR — HORSES.

Time lost — Sundays and usual holidays, 58 days.

Bad weather and half holidays, and
sickness, suppose - - 30

Making in all . . . . 88
Deducting 88 lost days from 365 leaves for working days
277, and makes the cost of each day ($93.53-j-277 ==)

not quite, cents 34

A hoy of 13 or 14 years, might hire for ^25 00

Food and clothing, two-thirds as much as a man's 18 12
Taxes (county and poor only) 80c., nursing, fuel,

&c., &c., $4 4 80

$47 92

10 per cent, for superintendence . . 4

80

Total yearly expense $52 72

And daily, for 277 working days, not quite, cents 19 1

Women and girls over 13 years, may be averaged at the same
expense, though worth less for labour.

According to the established custom, all the expenses of medical
attendance, and loss of time from the death of a slave occurring
when he is hired, are paid, or deducted from the hire, by the
owner, and therefore are omitted in this estimate. By supposing
the slave to be hired by his employer, instead of being owned, the
calculation is made more simple, and therefore more correct. Yet
it is well known that the labour of slaves owned by their employer
is much more profitable, and therefore should be estimated as
cheaper, than the labour of actual hirelings.
A worh-Tiorse. First cost in buying, at five years old, say $75 —

supposed to last six years, makes the annual wear |l2 50

Interest for one year on $75, and tax, 12 ^ cents 4 62 J

96 bushels of corn (2 J gallons for working days, and

2 gallons when idle) at 45 cents, and 3500 lbs. of hay

or fodder at 50 cents the 100 lbs. - - $60 70
Add 10 per cent, for expense and loss in

keeping 6 07

66 77

Interest on $66 77 fox one year - - - 4 00|

Total yearly cost, $87 89

whether going to marling or not, it is manifest that he is not affected by
any temporary fluctuations of prices of labour. The prices which will be
here stated as fair averages may fall or rise to any extent for a year or two,
without lessening or increasing the expenses of a proprietor who neither
hired, bought, nor sold labouring force during that time (1852).

MULES, CARTS, &C. 321

Lost time, suppose 98 days, leaves 267 working days, at nearly
33 cents,, cost for each.

A mule, young, and of better than ordinary or average ability,
usually may be bought for less price than a young horse. A mule
may be kept at work on much less grain than is necessary for a
horse, and with coarser and cheaper long forage. The mule is also
more long-lived. All these considerations will make the cost of a
mule's labour, less than that of a horse by at least one-fifth ; which
being deducted, leaves, (33 — 6.30 =) 26| cents for the cost of each
working day. *^

. A light tumbrel or tilting cart, for one horse or mule, may be
bought for $25. Suppose it to last at marling (and other uses) for
four years without repair ; or that at the end of that time it would
be worth as much only as all the previous cost of repairs. Then
the annual cost of " wear and tear'' would be one-fourth of the first
cost ($6 25) and the interest on $25, or $1.50, or annually,
$7.75; and daily (say for 190 days) 4 cents.

A tumbrel for two mules will cost $34, and will last at least five
years marling, with but slight repairs. Suppose the cart at that
time to be worth the previous cost of all repairs, the annual cost
will be one-fifth of $34, and of its interest $2.04, making ($34 -^
5 = $6.80-f $2.04 =) $8.84 for the yearly cost, and daily for 190
days, nearly 5 cents.

Harness for each horse or mule, annual average cost may be
supposed $4, and daily for 267 days in use, IJ cents.

Of the utensils used for uncovering, digging, loading, and spread-
ing marl, as a scraper (used very rarely), grubbing hoes, picks and
shovels, the cost of use^nd wear, supposed to be fully covered by
3 cents the 100 bushels of marl put out and spread.

In the estimate of the cost of horse labour, no charge is made
for attendance, because that is part of the labour of the driver, and
forms part of his expense. No charge is made for grazing, because
enough corn and hay are allowed for every day in the year ; and
when grass is part of his food, more than as much in value is saved
in his dry food. No charge is made for stable or litter, as the ma-
nure made is supposed to compensate those expenses.

It may be supposed that the prices fixed for corn, and fodder or
hay, are too low for an average. Such is not my opinion. The
price is fixed at the beginning of the year, when it is always com-
paratively low, because it is too soon for purchasers to keep swelled
corn in bulk, and the market is glutted. Besides, the allowance
for waste during the year's use (10 per cent.) makes the actual
price, equal to 49^ cents the bushel for corn, and 55 cents the
hundred for hay on July 1st. The nominal country price of corn
in January is almost always on credit ; and small debts for corn
are the latest and worst paid of all. The farmer who can consume

E22 ESTIMATES OF COST OF MARLING.

any additional portion of his crop, in employing profitable labour,
becomes his own best customer. The corn supposed to be used,
by these estimates, is transferred on the 1st of January, without
even the trouble of shelling or measuring, from A. B. corn-seller,
to A. B. marler, and instantly paid for. Forty-five cents the
bushel, at that early time, and obtained with as little trouble, from
any purchaser, would be a better regular sale than the general
average of prices and payments.

Tlie estimates of labovm applied to particular marling operations.

According to such estimates as the foregoing of the elements of
labour, or as corrected in any particulars which may be deemed
wanting, the expenses of marling operations ought to be estimated.
And if conducted with proper attention and judgment, it will be
found that, in the majority of cases in lower Virginia, the total cost
of applying marl, on farms furnishing the marl, would not exceed
one cent the bushel. In many other caees, of very favourable cir-
cumstances, half a cent the bushel would cover all the expenses.
In but very few cases of any known actual operations, and of rare
and great difficulties to encounter, ought the total cost to have
reached 2 cents. Yet even if amounting to 6 cents (for rich marl),
there would still be great profit on the outlay ; which is sufficiently
proved by the great and increasing recent use of water-borne marl,
•which is sold at 4 and 5 cents the bushel, delivered at the buyer's
landing, and which is further increased, for the carting to and
spreading on the field.

In my own long-continued and extensive marling labours, over
nearly all the arable land of three several farms in succession, I
have but in- few cases, and those of small extent, had very easy
work. Nearly all my marling has been of more than ordinary
difficulty, owing to the natural features of the land, and the posi-
tion and character of the marl ; besides the other early and great
difficulties always attending the first beginnings of new operations,
"without experience or other guidance. Yet, throughout all my
marlings (now extended to some 1500 acres, at more than the
general average rate of 400 bushels), the average of the whole ex-
penses ought not (as I would now conduct such) to have exceeded
one cent the bushel, spread on the field.

Such general opinions and statements, however, will be much
less SJrtisfactory than statements of actual labours and the actual
costs. I know of no such estimates of the easier and cheaper
marlings — which indeed are so easy and cheap that no one would
care to calculate the cost. None of my cheapest operations were
extensive enough to furnish subjects for fair estimates. For, unless
the labours, especially of the teams, are continued nearly regularly
for gome months, the accuracy of the estimates of cost may well be

COSTS OP MARLING. 323

doubted. It is necessary for the labours to be continued through
enough time to test the ability of the teams to perform them, and
still keep in good condition.

At different periods, and under varying difficulties and circum-
stances, I have carefully estimated the expenses of four considera-
ble jobs of marling, each of which was but a portion of the usual,
and as heavy labours of the teams, extending much beyond the
portions of time and labour particularly estimated. And all the
four operations, in greater or less degree, were attended with more
natural obstacles and difficulties than are generally to be encoun-
tered on other farms. I will describe in general the circumstances,
facilities, and difficulties of ^ each of these jobs, and give the results
of the estimates of costs. The details of the operations, though
carefully noted, and some of the earlier of them before published,
in the preceding editions, will be omitted here, except as to a more
recent and much the largest operation, of which the facts were
observed so minutely, that they are deemed worth reporting in de-
tail ; and which will be so reported in a subsequent chapter.

The labours and expenses of marling come under the following
four different heads: 1. Removing the overlay of earth; 2. Dig-
ging the marl and shovelling it into carts; 3. The carting to
the field ; and 4. The spreading. It rarely happens that all these
different operations are very easy — which would constitute the
cheapest possible marling ; and if all were very difficult, the whole
would be (or at least so deemed by most persons) too costly to be
compensated by the eventual improvement. It usually happens
that the unusual facilities for some of these particular labours serve
to compensate in some measure the obstacles presented in others.

The fii'st job estimated was attended with such uncommon dis-
advantages that it may be deemed a failure, or as mostly lost
labour, and therefore not a fair subject for estimating costs. But
as the operations had been carefully noted, and as this work imme-
diately preceded, without any intermission, the second job, I will
state the first also.

The two operations were but a small part of the excavation and
removal of a very large quantity of marl from this locality, enough
perhaps for 200 acres ; of which the portions estimated were among
the latest executed; and the most expensive, because of the then
much increased thickness of the overlying earth.

The marl "cropped out,^' or was exposed at the surface of a
steep hill-side (in large forest growth). The upper 6 feet of the
marl was dry and firm, but easy enough to dig ; the shelly portion
in small fragments, and amounting to 45 per cent, of the mass.
Below 6 feet, it was much poorer (not 20 per cent.), and was not
used, except for very short distances.

I. The excavations for the first job, as usual on hill-side expo-

32-4 COSTS OP MARLING.

Bures, was carried on by first cutting down the exposed and nearly
naked marl, which required but little labour for uncovering. The
next succeeding stretch reaching higher up the hill, had perhaps
as much overlying earth as of good marl beneath. The next had
much more overlay ; and indeed it was not worth uncovering so
deeply, when other places could be more cheaply worked. This
last stretch formed the subject of the first estimate. In reference
to the four divisions of the labour and expenses —

I. The removing of the overlay of earth was here unusually
heavy, compared to the thickness of the marl, rising to 16 feet
where thickest, and averaged 11 to 12. 2. The digging and load-
ing, and also the spreading, were very easy. 3. The carriage easy
as to distance (997 yards average from pit to field), but bad in ,
having a hill to rise of about 40 feet perpendicular height, and
also a valley to cross, of about 30 perpendicular depth.

One-fourth of the uncovered marl tras lost by the falling in of
a large body of earth from above; so that only 4 J feet of marl
was actually carried out, thus increasing the before heavy cost of
the uncovering, for the quantity of marl saved.

Under these circumstances, the total costs, obtained by noting
every day's work, and its elements, and at the foregoing prices
(omitting the details), were as follows : —
Expense of removing overlay of earth (11 to 12 feet thick

on an average) ....... $24 70

Digging, loading, and carting marl (3844 heaped bushels) 26 18
Spreading, at 50 cents the 500 bushels . . . . 3 84

Total, $54 72

Which makes the cost per 100 bushels, $1.42 ; and per acre, as
applied, at 572 bushels, $8.12; or if for 300 bushels, $4.26.

The quantity actually applied was*much too heavy; and by the
excess increased, by one-third, the otherwise heavy expense. The
thickness of the dressing, however, made the spreading cheaper
for the quantity, the heaps being so much the closer to each other.

II. The second job followed on immediately, but on the opposite
glope (across the narrow ravine), where the overlay was 82 to 9
feet average depth, and all the 6 feet of good marl was used. The
average distance from pit to field (over the same hilly road), was
887 yards. The marl being precisely as in the first job, the facili-
ties for digging, loading, and spreading were the same. But the
loads (for a single horse or mule-cart), which before were 5 J heaped
bushels, were now 5f — the marl weighing 101 lbs.

Removing overlay ...... $14 15

Digging and carting marl (4036 bushels) . . 20 75

Spreading, at 50 cents the 500 bushels . . . 4 36

Total, $39 26

COSTS or MARLING. 325

Which makes the cost, per hnndred bushels, 971 cents; or, per
acre, as applied, at 598 bushels, $5. 81 J; or, if at 300 bushels,
which would have been an abundant first dressing, $2.9 li per acre.
These two jobs extended, without interruption, except from bad
weather or accidents to carts, from April 20th to May 31st, 1824.
Two ordinary horses and a very good mule were worked in light sin-
gle carts. The best of the two horses was seventeen years old. The
two had been kept at hauling marl, whenever weather permitted,
from the beginning of the preceding November ; and, indeed, the
same two horses had carried out nearly all the marl on Coggins
farm, since the commencement in 1818. The day's travel from pit
to field and back, for both the two jobs, varied from 22 to 23 J
miles, besides about IJ miles in all from and to the stable. For
the digging, loading, and carting, two men and two small boys were
employed.

III. The third estimated job was on Shellbanks farm, also in
Prince George county, over a much larger surface than the preced-
ing, but from sundry different pits, over difi'erent routes, and to
different fields. The overlay was mostly thinner than the marl
beneath, and both were dry in most cases ; the working of both
easier than usual ; the distances moderate, the average from pits
to fields being not more than half a mile ; though the land being
hilly, almost every load had to rise a hill from the pit, from 40 to
100 feet of perpendicular height. In 1828, soon after buying this
poor farm, I began the marling, and in about 4 months finished
1201^ acres at rates between 230 and 280 bushels per acre. The
time taken up in this work was five days in January, and all Febru-
ary and March, with two single mule carts (and but ordinary
mules), and from August 5th to September 27th, with a much
stronger force.

Taking everything into consideration, I should suppose that the
labour and cost of this large job of marling will be equal to, if not
greater than the average of all that may be undertaken, and
judiciously executed, on farms having plenty of this means for im-
provement, at convenient distances. The whole cost of this large
job was as follows : —

Preparatory work, including uncovering marl, cutting
and repairing the necessary roads, and bringing corn
(from another farm) for the teams — digging, carrying
out, and spreading 6892 loads of marl (4 J heaped
bushels only, because of the steep hills, and sometimes
wet marl), 31,014 bushels on 120 ^ acres, - - $265 90
At the average rate of 57i loads, or 259 bushels per

acre, the average expense was to the acre, - - 2 28

Or $2.58, if for 300 bushels to the acre.
And ta the bushel, - - 86-lOOthB of a cent.
28

326 COSTS OP MARLING.

In this job, the quantity of labour of every kind employed, was
accurately noted, and also the amount of marl carried out ; so that
the cost could be very exactly calculated. But owing to the great
and frequent variation of distances from the various pits opened,
there was no measurement of the travel made, and of course the
proportion of work performed to the force engaged was not known.

IV. The next job of marling estimated was in 1844, on Marl-
bourne, a farm on the Pamunkey river then recently bought, and
made my residence. This is the operation of which the facts in
detail will be given hereafter. Therefore it is enough to state here
that the total cost of 7803 bushels, carried to the average distance
of 1436 yards from pit to field, amounted to 94 cents for the 100
bushels of marl, spread on the land.

Thus, of these four considerable operations, performed at diffe-
rent periods, and under different circumstances, of which one only
can be deemed of ordinary facility and cheapness, and one other
was excessively laborious and expensive, the costs brought together
are as follows : —

1st, on Coggins Point farm,
2d, *' " «' ««
3d, «' Shellbanks,
4th, " MarlboTU'ne,

Cost per 100
heaped bushels.
$1 42
0 97^
0 86
0 94

Cost per acre if

at 300 bushels.

$4 26

2 92

2 58

2 82

But not one of these operations was as judiciously and cheaply
executed as my more full experience would now direct; and if
either one were now to be done, I could save much of the labour
before expended. Nor does this rest on supposition, but has been
actually tested by further and large operations in the same locality
and circumstances as of the fourth in the above statement. By
improving the processes, or avoiding previous waste of means,
something has been saved in every branch of labour, as will here-
after be shown.

CHAPTER XXIX.

DETAILS OF ACTUAL AND EXTENSIVE MARLING LABOURS.

The largest known uncovering and excavation of marl is that
•which was begun by me in 1844, soon after my resuming marling
labours in a new locality, and under new circumstances ; and which
work was in progress to 1850. This work is deemed worthy of
being particularly described, for the extent and the mode of opera--
tion ; and still more because some or all of the same general features
of the locality, and advantages and difficulties, belong to very many
other situations, of low-lying marl. It will not be my aim, in this
place, to describe the general character or to note differences of the
extensive marl formations of the Pamunkey river ; but to state
minutely the particular conditions of this one locality, and the
labours there actually performed.

The place is on the Newcastle farm, belonging to Carter Braxton,
Esq., and adjoining my own. The ground is part of a long and
narrow stretch of the lower and more sandy land of the broad
flats bordering the Pamunkey. The surface soil, covering the dig-
gings to be described, is nearly level, but gradually rises^ and the
earth overlying the marl increases in thickness from 4 feet, in the
earlier work, to 6^ at its greatest present enlargement. The sur-
face of the bed of marl is also very nearly horizontal ; and the vari-
ations from the level do not. agree with those of the surface soil.

The marl originally was here exposed to view by being partly
cut through by a narrow gully conveying a small stream ; which
stream received all the drainage of the adjacent land, and thereby
was subject to be swollen by heavy rains. The stream, naturally,
was about 2 feet below the highest exposed marl, and about 4 feet
above the bottom of the bed at the same place. Except the con-
tinuation of this stream, and the narrow ravine conveying it, which
very gradually descended to the river, all the adjacent ground
was at least four feet higher than the upper surface of the marl.
The annexed figure will show the profile of the difierent layers, at
the distance of 40 to 60 feet from the stream.

(327)

828

Overlay.

PAMUNKEY MARL.
FlGUB-E 1.

' Sandy surface soil, about 6 inches

Sandy sub-soil, dry and firm ">
Loose and dry sandy gravel /

Indurated ferruginous sandy ")

Feet.

gravel, wet, 1 foot

Wet and adhesive green clay, ("olive earth") 1 foot

Marl.

Soft and pervious clay marl, 6 inches
Compact and impervious clay marl, 5 feet

Softer layer, 1 foot

Layer of stony lumps, 1 foot

Gypseous, or green-sand earth, with very little shelly mat- )^
ter, of great and unknown thickness — at least 40 feet j

0^

H

40

The soil of the overlying land is a rich black sandy loam (before
drained and cultivated), 6 or 8 inches deep, lying on a sandy
subsoil, firm and dry, and becoming more coarse and loose as de-
scending, until it is more of fine gravel than sand. All the above
layers, varying from 2 J to 4 feet in the successive uncoverings, are
dry and easy to dig and remove. Below these, the gravelly sand
is more or less cemented into a hard and almost stony bed, by the
percolation of ferruginous spring water. Under this layer, which
is full of veins of springs, coming from beneath the higher ground,
there lies a very uniform layer, from 8 to 14 inches thick, of green
clay, which is the water-bearing stratum, and keeps the lower part
of the gravel above full of water. This green clay has a very pe-
culiar appearance and texture. Though very largely constituted
of pure clay, and extremely adhesive and close after being moved,
yet in its bed it is very soft and pervious to slowly-oozing water,
and, of course, is saturated by the numerous veins of springs above.
I think that this green clay was formerly the. upper part of the
marl ; and has had all its former shelly matter decomposed and
carried off by the constant access and passage of water containing
salts of iron. The upper 4 to 6 inches of the marl immediately
below this clay, seems as if in transition to the same state. It is
soft, permeable by water, miry, and adhesive, all which are qualities
of the clay above, and entirely different from the compact marl

EXCAVATION OP SMALL PITS. 329

below. Although this lower marl also contains a large proportion
of clay, yet the carbonate of lime present, in finely-divided state,
not only preserves a very firm natural texture, but also prevents
adhesiveness in working; unless the marl is permitted to receive
water after being dug and finely reduced. Then, indeed, it is made
a sticky mass; and the labour of shovelling it is more than doubled.

The whole bed of marl at this place varies from 6 to 8 feet in
thickness, and generally is more than 7 feet, through the extent
of my work. The much larger part, of 4 to 6 feet thick, is per-
fectly impervious to the passage of water, though highly absorbent
of moisture, and always moist in its bed. This requires to be dug
by a heavy and narrow grubbing-hoe, which, in the hands of a good
pit-man, can be sunk barely 3 inches into this marl at a stroke.
Still lower, for a foot or more, the marl is softer, and the shells
are less reduced. And lowest, also for about a foot, the marl is in
large stony masses, lying so closely as to form a connected pavement.
The breaking up of this stony layer requires heavy and strong
picks, and the work is laborious and slow. But these hard lumps
are much richer in lime than the marl above. The excavation is
carried no deeper than through this stony layer ; and even that
has often been omitted, on account of the greater labour to dig,
and to throw it up from the greatest depth.

Next below this stony layer is the green-sand earth, of great and
unknown depth. Here, this contains only about 2 or 3 per cent,
of carbonate of lime, in a few widely dispersed shells, with the
usual and considerable proportion of green-sand. I do not use this
etirth, nor deem it worth using as manure, where the upper marl
is to be obtained. Nevertheless, this lowest bed was formerly used
by the proprietor, and by others, in this neighbourhood, as "marl,''
without discrimination; and it was then even preferred by most
persons to rich calcareous marl, if the latter were withaut green-
sand.*

Excavation of Marl in small perpendicular pits.

The first working was begun by digging and throwing off the
overlay adjoining a part of the narrow " out-crop" or exposed marl,
on the side of the natural gully through which the stream flowed,
so as to uncover a surface of marl 5 or 6 feet wide and 8 or 9 in
length (marked 1, in fig. 2). So narrow was the gully, and so lit-
tle fall had the stream, that it was difficult to dispose of the earth
from even this small uncovering. The marl was then dug out, so

* The description of the strata is here generally confined to such features
as materially affected the labours of excavation, and removal of the overlay
and marl, or the supposed manuring values of the lower beds. In a subse-
quent part, in connexion with the marls of Virginia in general, the Pa-
mmik^y beds will be more fully described.

330

MANNER OF EXCAVATION.

Fia. II,
Horizontal Plan of Marl Diggings,

^ ;.::.::=:::=

''T^

■ ' . - ■ ■ :,^

Explanations. Fia. II.

«) X — Stream, in a small natural ravine, on the sides of wliicli some of the
marl was exposed, at the out-cropping.

A, A — the first range of marl, successively uncovered and excavated in the
small perpendicular pits 1, 2, 3, 4, &c.

B, B, and C, C — second and third ranges of diggings, in like manner, but
increased in sizes of pits.

D, D, D — at first the natural surface of ground (5 feet above the marl), on
which the marl was thrown out of the pits of range C ; and next after,
D, D, D, was the first range of graduated digging. ^

c, d — the upper part of D, 96 feet long, the overlay but partly removed at
first, so as to form an inclined plane for the roadway. The same de-
scending grade continued in excavating the marl from d to e e.

e, d, e, e — ^narrow drain cut first down to, and afterwards into the marl, to
intercept spring water, and turn it into the stream x — and thus to drain
the space D D.

ff, g — farm road, on level, opposite ranges D, E, F, G, rising from 5 to 6^
feet above the marl.

A, A, A, h — upper ends of roads successively used from the graduated dig-
gings.

0, 0 — Slower ends of descending roadways in the marl.

E, F, G — successive ranges, uncovered and excavated in graduated diggings,
similar to D, but increased In extent.

H, H — ^range 86 feet wide, uncovered for next working — and less than half
the marl of which was excavated, when my operations at this place were
finally closed in December, 1850.

N. B. The Fig. II. is drawn on the scale of 80 feet to the inch, for the
dimensions of ranges, and the general outline and space. But small sizes,
and distances, as width of drains, &c., are necessarily irregular, and much
larger than the scale.

(331)

382 EXCAVATION dP SMALL PITS.

as to form a pit with perpendicular sides, and thrown npon the
adjoining firm ground (on 3), whence the carts removed it nearly
or quite as fast as supplied from the digging. This small excava-
tion served to receive the removed overlay from the next adjoining
and larger uncovering (2), which, when pitted, in like manner,
received the overlay from a still larger space (3). In this manner,
successively digging out small pits with perpendicular sides, and
then filling each one with the earth removed to uncover adjoining
and enlarged spaces, the whole of the first irregular range (A A A)
was worked out, between the stream (^x) and the line a b, then the
lower limit of the firm overlying surface ground, on which the marl
had been thrown for the carts, from the previously dug range of
pits. So far, the work had been on the thinner out-running of the
strata, and the sloping overlay not any where more than 4 feet thick.
But thin as it was, and close to the places where thrown, the re-
moval was lajaorious, owing to the oozing spring-water, and the
adhesive clay, made much worse by the quantity of water. Of
course, for such small and frequent uncoverings the previous cutting
off of the access of springs was out of the question. This difficulty,
caused by the water being necessarily worked up with the clay and
other earth, increased with the increased width of the uncoverings,
and the distances to throw off the earth. Each small uncovering
of marl, after all its overlay had been removed, was separately
drained, by a small trench being dug in the marl along its land
side, and catching and leading the intercepted oozing springs into
the previously made and still partly open excavations. As the
marl was thrown up across these draining trenches, they were fre-
quently choked by the marl, falling back. This was partially
guarded against by laying a thick plank over the trench. Walls
of marl, 15 to 20 inches thick, were left between each completed
pit and the next one begun, to keep out of the newer work the
mud and water which filled the older. But after each pit was
finished, more or less of the wall previously left was cut down, and
so much of the marl saved. Still, there was much loss of marl in
what was necessarily left of these walls. Besides, other losses were
sometimes caused by floods from heavy rains, or the breaking down
of walls, filling unfinished diggings with water or mud too deep to
be worth the cleaning out.

Along the first range of digging (A A A), the stream was higher
than the bottom of the pits, from 2 feet at the beginning (1), to 4
feet at the upper end (a). Its water was kept out of the diggings
by leaving a narrow wall of marl alongside of the stream. This
served as a barrier until each pit was finished ; after which the en-
trance of water caused no serious inconvenience. As the pitting
was extended up the course of the stream, the thickness of the
marl stratum increased to 8 feet. The lowest stony layer, however,

EXCAVATION OP SMALL PITS. " 833

was tlien generally left ; being not deemed worth the great labour
of throwing it up so high. The overlay being there 4 feet thick,
the extreme height to raise the marl was 12 feet from the bottom
of the marl to the surface of the ground where the carts were
loaded.

In this manner of working, were successively uncovered and
excavated the next ranges, B B and C C. But before either range of
marl was near being finished, the removal of the next succeeding
overlay had been begun and was extended at convenient times, and
especially when the wet or frozen condition of the land forbade
most other farm labours. At such times, the worst previous
weather but slightly impedes the uncovering of marl ; and thus a
large proportion of this heavy labour has been performed when
scarcely any other farm work could be done. This circumstance
greatly diminishes what would otherwise be the expense.

The digging of the first marl (1 in A) was begun on June 28 th,
1844. The excavation of the third range of pits, CC, was finished
the following April. This last range was 250 feet long, 15
feet wide on an average ; and measured 25,800 cubic feet in the
bed (allowing a proper deduction for lost walls and bottoms), which
would expand to about 29,670 heaped bushels after being dug.

The separate pits of the wider and more regular range C C were
much longer, as well as much wider, than those of the earlier ranges.
They were the full width permitted by that of the uncov-ered marl,
clear of the narrow drain on the land-side, and the wall left on the
opposite side — or about 13 feet. In length, they were 15 to 20
feet, or more, to suit the amount of labour engaged. In the
usually dry weather of summer and autumn, and even in winter
when a strong force was employed, there was the less danger of
having unfinished work suspended by rain, and lost by oVerflow
of water, or caving earth ; and then larger diggings were opened.
By increasing the size of the pits, there was the less trouble in
constructing new drains, less loss in the dividing walls left, and
more space and convenience for the pit-men. Besides, there was
the benefit of equalizing the labour of throwing out the marl, by
keeping the digging on two difi"erent levels at the same time.

The still slightly increasing thickness of the overlying earth
made that of the next range (D) 5 feet ; to which height, of course,
the marl was thrown from the pits of C, making the perpendicular
height from the top of the marl 5 feet, and from the bottom, 13
feet, when all was dug ; or 12 feet when the stony bottom layer
was left, as was now usual. But to make sure of the thrown marl
not falling back into the pit, and especially when there was some
quantity of marl remaining in the pile in advance of the carting,
the height of the pit-man's cast was necessarily considerably more
than the mere depth of the then excavation. Added to this was

834 LABOURS OP A SINGLE MtH^.

all the lateral distance, which where greatest of the range C, and
from the outside of the pit across to the loading place, was usually
14 and in some wider parts 17 feet. This throwing of the marl
from the greatest depth and width of the pit was very heavy and
slow work.

It was after the usual steady work of my then regular marling
force, begun the 24th of the preceding January at another digging,
and continued whenever the state of the weather and roads per-
mitted, that the excavation and carting were begun at this digging
on June 28th, 1844. On April 29th, previously, I had begun to
measure and to note the quantity of marl carried every day by
each cart, and the distances travelled ; and of which the record
was carefully and accurately continued until Sept. 11th (with the
exception of a few days only, when the teams were at other work),
for every day when the weather and roads permitted marling.
Though noting thus the work of every separate cart and team,
whether regularly or rarely so employed, the trial was especially
designed for one particular mule, which was always kept at hauling
marl (when that work was going on), and which has continued to
be so employed to this time, in 1849. This mule is rather above
average size, and might have been sold for $65, according to the
prices usual in and before 1844. She had begun this labour
in January, when poor ; had improved while so employed ; and
was in excellent working condition when marling was suspended
in September, for the purpose of all the mules being used for the
heavier labours of fallow-ploughing for wheat, and afterwards har-
rowing in the seed. I could extend the statement of this mule's
daily work, as particularly, by embracing what had been previously
observed and noted from April 29th, and also of all the other
teams, irregularly employed. But it will be enough to present the
portion of work done by this one, and only from the beginning of
the "excavations at this locality, of which the circumstances, and
for this purpose, have been so minutely stated above. It is only
by such careful observations, and actual measurements of quanti-
ties and distances, and these, moreover, continued for a considera-
ble extent of time, that any fair and unquestionable evidence can
be afforded of the amount and cost of any labour that can be per-
formed in a certain time, by men or beasts, and especially of the
latter. For a few days, or perhaps for a few weeks, there might
be performed labours which the teams would sink under if con-
tinued much longer. But when a certain measure of work has
been done regularly for months together, without any apparent
difficulty or hardship to hands or teams, still more, when the teams
have improved in flesh while continuing and even increasing their
daily labour (as in this case) , there can remain no question as to

DIRECTION OP LABOUR. 335

the ability of all to continue to perform the same amount of labour
for any length of time, under like circumstances.

From the commencement of my marling on my then newly-pur-
chased farm, Marlbourne, two mules were assigned to this work,
to be regularly so employed in all time fit for hauling marl, except
during the greater pressure of certain other farm labours. These
times were to be during wheat harvest (when only for eight or ten
days all the mules usually would be idle, because all the drivers were
needed as harvest hands), when hauling out the stable and winter-
made manure — hauling in and thrashing the wheat crop, and deliver-
ing the grain for market at the river landing — for the ploughing for
fallow wheat, and ploughing and harrowing when seeding — and to
plough the corn for a few days both before and after wheat harvest
— and sometimes when hauling in the corn crop, if hands could
not then be spared to dig marl. None of these labours, except
hauling in wheat and corn from the fields, are lighter than would
be the continuation of hauling marl ; and some of them (fallow-
ploughing, harrowing, and thrashing) are much heavier. All these
different operations usually kept the marling suspended for times
amounting to about half the working days of each year. But not
so much in 1844, as there was then no wheat crop to harvest or
thrash, and very little manure made to be carried out. All these
abstractions of the regular marling teams are much more than com-
pensated by the irregular employment, at marling, of the ploughing
teams at what would otherwise be their idle or leisure times.
There is much convenience and gain in having labour thus to be
exchanged. At the pressing seasons of harvesting, fallowing, for
seeding and thrashing wheat, the regular farm force is insufficient,
and no supply of extra force can be hired. Then the other force
kept for marling becomes an important aid, and is worth much
more than the cost, or than the marling labours thereby postponed.
On the other hand, the regular carrying on of marling operations
by an extra force so applied, enables the farmer to increase it at
any leisure time, by any surplus force, of hands or teams necessarily
kept for farm labour ; and whose surplus or spare time, for short
intervals, could not otherwise be put to any profitable use. In the
one case, force that would be cheaply hired at double of average
price of hires, is obtained for the lowest rates ; and in the other,
for no more than the cost of maintenance. Without both these
reciprocal aids thus exchanged, I am sure that my wheat crop would
necessarily be curtailed by one-sixth, and my marling by more
than one-half.

The statement to be here offered of a connected portion of the
marling labours of 1844, will be of what was actually done, under
the then existing circumstances, and with the then defective mode
of working — and not of what might have been done with better

836 DETAILS OF OPERATIONS.

appliances and more experience, or with such improvements of
operations as I have since introduced.

The distances from the pit were accurately measured; except
for inconsiderable and daily variations from, or extensions of known
distances, which were estimated by the less exact measure of my
stepping. For every new route, and every considerable alteration,
the measuring tape was used. The contents of the cart-bodies were
ascertained both by cubic measurement and by the heaped half-
bushels of marl which could be put in. After enough of such trials
had been made for fixing an average, each cart-load, accord-
ing to its being filled even, or slightly heaped, or fully heaped
(which variations might be required by different conditions of
teams, marl, or roads), was respectively taken as the measure of a
stated number of bushels.

Single mule carts were used this year, which was one of the
errors afterwards abandoned. Tht3 loads of the one mule whose
work will be separately stated, was at first made 8 heaped bushels^
afterwards increased to 8i. Her driver was a boy of 15 years old.
Two other mules which were generally but not regularly hauling
marl during the same time, were driven, one by a boy, and the
other by a girl, neither driver exceeding 13 years old. Tasks were
assigned to each mule cart. Marling is the only kind of farm
labour that I ever could have performed advantageously by task-
work. For this, tasks were found very advantageous ; and no
other work which has been under my direction has been executed
BO faithfully, or with so little superintendence or difficulty. This
peculiar adaptation to task-work is owing to the uniformity of the
labours, when conducted on a regular plan of operations.

The marl was very generally free from all extraneous water.
Though moist in its bed, and when dug, it is as little so as any
highly absorbent earth could be, if in like manner covered by wet
and water-soaked clay. The marl, just after being dug, weighs 105
lbs. to the heaped bushel. If allowed to become wetter, its weight
is much increased. I found, by trial, that a bushel of this marl,
as moist as when dug, would absorb two gallons more of water (16
lbs.), without being so surcharged that any would drip away. Yet
many of those persons who work marl having springs oozing out
above, allow so much water to have access, as to add much more
than 16 lbs. to the weight of the bushel of marl, and to increase
the labours of shovelling and loading in still greater proportion.

The degree of inclination of the surface of the land on which
marl is carted, and its being rough or smooth, soft or firm, all have
important influence on the labour of marling. The land to which
mine was then applied, as well as all over which the routes passed,
was part of the broad flats bordering on the Pamunkey. The very
gradual ascent from the margin of the pit (where the marl was

CONDITIONS OP THE LABOURS. 337

thrown up, ready for filling the carts), was not more than 10 feet
of perpendicular height, to the highest summit ; after which, the
routes to all the difierent places of deposit pass over slight and
gradual undulations of surface, as much descefiding as ascending,
and which variations of level, in their extremes, scarcely exceed 6
feet. So level a way is of course a great advantage, and enables
me to carry much heavier loads than on the high and hilly lands
which I formerly marled elsewhere. But, on the other hand, this
almost level surface requires the land everywhere to be ridged ;
and the water furrows (or deep alleys), and the many deeper
cross " grips" (or very narrow and shallow ditches), together pre-
sent greater obstacles to the passage of carts over the fields, than
would be found with much more of ascent and inequality of sur-
face, but with smooth tillage. Another disadvantage, suffered then,
and generally for some years after on nearly all my land, was, that
as it had not been recently grazed and trodden by cattle, the soil
was not firm, but puffy and soft; and therefore, even when dry, and
still more when wet, this soft soil greatly increased the labour of
carting on the fields.

The marl contains, on the average, 88 to 40 per cent, of carbo-
nate of lime. It was applied at about 350 bushels to the acre — in
heaps, 11 yards each way, of the whole load of a single mule, or
half the load of two mules, or two oxen.

After all these matters of preliminary explanation, I will now
present the particular statement designed, showing for an entire
job of 64 consecutive working days, the daily travel, and number
and amount of loads of a single mule ; and also the total quantity
of marl dug for and carried out by other and less regular teams,
whose work, though noted separately, it is not necessary to give
more particularly in this abstract from the fuller record in my
farm journal. The work stated in the following table comprised
all the marl of the ranges A and B, and a large part of the next
and wider range G.

29

338

ACTUAL MARLING LABOURS.

1

HAULING BY ONE MULE.

1 Whole Work.]

1 .

II

Average dis-
tance from
pit to field f
(and back). ^

Whole day's journey,
Additional including distances to

II

Days.

1

distance a
rom stable. -

nd from stable.

-^

s

Miles. Yards.

June 28

12

of 8

1770 X 2

380X4

25.

2

310

" 29

12

i(

((

"

25

«

308

Monday,

July 1

-11**

(I

u

«

22.1740

a

302

« 2

12

it

<(

«

25.

iC

304

« 3

12

«

u

<<

25.

«

310

« 4

12

«

C(

<c

25.

«

346

" 5

12

«

1825

296

25. 984

"

346

« 6

11

M

1866

274

23.1576

«

316

M. " 8

11

«

1883

208

24. 18

(I

316

" 9

10

((

2245

none.

25. 900

(C

272

" 10

7*i

«

"

«

15.1510

«

154

« 11
« 12

13?
10

274
246

(t

2245

none.

25. 900

«

« 13

20

11

965

1005

24. 380

"

274

M. " 15

20

it

915

955

22J600

11

274

« 16

20

((

a

a

22.1600

a

274

« 17

20

U

939

u

23.900

"

274

« 18

20

(I

963

«

24. 100

3

354

« 19

20

u

971

«

24. 420

«

402

« 20

12*1

«

984

955X2

23. 2^58

«

250

M. " 22

20 "^

«

995

955X4

24.1300

a

330

" 23

17*1

<«

«

20.1450

5

604

« 24

2H

«

1012

855

26. 160

"

716

« 25

19*

«

23.1396

i(

746

« 26

13*a

<(

1378

652

23.1156

"

532

« 27
M. " 29

15

((

1408

i(

25. 848

2

324

« 30

15

«

«

i(

25. 848

3

500

" 31

15

»

«

«

25. 848

"

514

Aug. 1

15

((

«

«

25. 848

"

498

" 2

14*6

it

1263

707

20. 164

"

506

« 3

16

u

a

«

24.1004

"

536

M. " 5

16

«

11

u

24.10M

C(

500

" 6

16

«

1293

677

25. 184

(I

500

« 7

18

«

1069

901

23.1608

«

530

« 8

16

«

1323

647

25. 924

«

529

" 9

16

C(

«

«

25. 924

«

510

« 10

16

«

((

«

25. 924

(C

460

11. " 12

16

«

1363

607

26. 284

I<

514

« 13

15

«

1374

596

24.1364

«

592

« 14

15

((

1395

575

25. 184

«

596

« 15

15

(C

((

25. 184

"

596

« 16

19

((

1091

880

25. 978

((

585

« 17

19

«

"

25. 978

((

585

M. " 19

15

«

1428

522

25. 928

a

543

" 20

15

«

25. 928

a

470

« 21

19

«

1110

857

25.1608

2

253

" 22

19

«

1234X2

836X4

26. 676

2

278

" 23

18

of S%

1154

816

25. 808

"

271

« 24

18

Of 81^

«

((

25. 808

"

271

M. « 26

12

1865

none.

25. 760

3

530

« 27

18

«

1154

816

25. 808

3

540

" 28

18

((

1176

794

25.1512

«

579

« 29

18

«

((

"

25.1512

«

556

« «0

18

((

1200

772

26. 528

«

489

« 31

10*c

oT 8}^
of fU

«

15.1688

«

283

M, Sept. 2

17

; 1222

750

25. 448

"

613

" 3

12

1865

none.

25. 760

«

403

<' 4

12

«

«

25. 760

2V

2</

i 403

« 8

n

«

«

u

25. 760

2 450

« 6

13

«

«

«

27. 970

2

428

« 7

12

«

i(

«

25. 760

2

'283

M. « S

12

((

((

((

25. 760

3

639

« IC

12

i(

"

«

25. 760

4

672

« 1]

10*..

1

Loatle.

i(

«

21. 340

4

334

• ^i

1.547. 270

leSTlMATES Of MARLING LABOUES. SSO

REMARKS.

* The numbers marked thus (*) are short of full day's work, for causes
to be stated.

** July 1, one load, or one-twelfth of the task, lost by rain.

*f July 10, rain prevented 3 loads, or three-tenths of the task.

f July 11, full but irregular work at another place, and distances not as-
certained— the ordinary road being too wet to use.

*| July 20, stopped at 12 o'clock for half holiday— 8-2 Oths of full day's
work wanting.

|f July 23, rain caused loss of 3 loads, or 3-20ths of task.

I July 24, a load too much, by mistake.

*cf A good rain in afternoon — 2 loads (2-15ths) lost. Next day (27th)
earth too wet for marling, and the mules at the harder work of ploughing
for wheat.

^b Aug. 2, rain caused loss of 2 loads, or 2-16ths of task.

*c Aug. 31, stopped at 12 o'clock for half holiday, 8 loads, or 8-18ths
wanted of full day's work.

*c? Sept. 11, rain, after long drought, stopped all work at 4 P. M. Next
day more and heavy rain, and this mule, and all others fit, put to plough-
ing for wheat. For two weeks previous to these rains, the ground had
been excessively dry, so that the road, and tracks across the fields, which
were constantly travelled over, were so deep in fine dust that it was very
unpleasant, and even an impediment to the teams.

The foregoing table gives the following results : —
The mule, whose work is stated separately, in 65 consecutive
days, omitting the Sundays only, travelled in marling labour 1572
miles and 408 yards. Of these 65 days, 1 (July 27th), the teams
were at other labour. One other day (July 11), of full but not
measured marling labour, being estimated and added in at the
general average, and of 8 other days,* of which the work was bro-
ken by rains, the idle parts being deducted, leave 62 i of full work-
ing days of hauling marl. This makes the daily average travel of
the mule 25 miles and 138 yards, including the distances from the
stable and back.

The whole number of loads actually carried out by the one mule
was 965; the average load, in heaped bushels, 8.095, weighing 105
lbs. to the bushel, and 850 lbs. the load. The average number of
loads daily (for full day's work), was 15.4 ; and the average travel
for each load, 2867.4 yards.

The quantity of marl carried out in 62 J full days' work, 7803
bushels ; which makes the daily average quantity carried, 124.85
bushels.

And as to the general operations of all the force employed —
The whole quantity of marl dug, and carried out by all the
teams, in this time, 26,271 bushels.

* The parts of the 8^ days lost by rain or othei-wise, amounted in time
to much more than 1^ days. But the loss in work was no more, because
in every such interruption, the hauling, or task-work for the day, was in
advance of the hour when operations were suspended.

840 ESTIMATES OP JlAItlWCt LABOURS.

The wliole digging and throwing out of the marl, and assisting
the drivers generally to load (which assistance by one of the pit-
men was required always, but not always given to all of the extra
teams), was equal to 177 days' labour of a single pit-man; which
makes the average quantity of marl, dug, thrown out, and partly also
loaded, for each pit-man, 142.42 bushels.

So much for the labours actually performed. I shall now proceed
to estimate their cost. For this purpose, the different kinds of labour
will be charged at the prices stated in the previous chapter.

Estimate of the cost of Marling.

Carting. — The mule per working day, cents, . . 26.75

Her driver, (boy of 15 years,) cents, 22

Cart and gear, suppose, cents, ... 5.50

For daily work, an average of 124.85 bushels, . 54.25

Or, for the 100 bushels, cents, ^ 44.26

Digging and assisting to load. — Pit-man, per day,

cents, 34

His share of tools, suppose, cents, ' 4.50*

For his average daily work, of 148.42 bushels, . 38.50

Or, for the 100 bushels, 26-

Throwing off overlay of earth to uncover marl (its
thickness compared to that of the marl about in
proportion of 3 to 5), supposed to be one-half the
labour of pit-work of the marl below ; or per 100

bushels of marl dug, 13.

Spreading marl (340 bushels to the acre,) per 100

bushels, flO-

Total cost of applying 100 bushels, 93.26

* This charge includes all the use of tools for as much marl as one pit-
man supplies in a day, not only for his own digging and throwing up, but
also for the loading and subsequent spreading of the same marl.

■j- The spreading of this marl requires very unequal labour according to
its condition. When recently carried out, and still moist, and much of it
in firm lumps — or otherwise, after mouldering by exposure, and then being
saturated by rain-water — it is twice as difiicult to spread as after being left
in heaps for some months of summer weather, or until dry after being fro-
zen. When in good order, a man can easily spread 60 heaps of 8 to 9
bushels, at 11 yards distance. AVhen but in tolerable order, and in winter
days, I have had 50 such heaps spread by good hands ; and when in bad
order, barely 40 heaps. Thinner dressings, or more distant heaps, would
require more labour for spreading, in proportion to the quantity. The
charge above, a man (at 34 cents a day) is allowed to spread per day no
more than 40 heaps, of 8 J bushels to the acre. This is very light work,
unless the marl is m. bad condition.

SUMMER AND WINTER MARLING. 341

Small as is this cost for a durable manuring, it far exceeds what
would be required on most farms possessing marl-beds. In many
localities in Virginia marl may be uncovered, excavated, and car-
ried to the field for one-half of my expenses for the same; and in
some cases in Virginia, and in Numerous situations in South Caro-
lina, the necessary expenses would scarcely be more than a fourth
of mine. The spreading is not included in this comparison, as its
cost has no relation to the greater or less cost of the other labours.
The obstacles to my operations were unusually great — in the soft
and adhesive overlying clay — the numerous small springs necessary
to be diverted — the liability of the loose sand above to be washed
down by rains — the low level of the marl compared to the sur-
rounding land — and the great distance from the pit to the field.
But whether the difficulties of other marlings be greater or less than
mine, their costs may be estimated by my rules and prices, with
due regard paid to difierence of circumstances. Before, however,
making such application, regard should be paid to the improved
processes and reductions of expense in my subsequent operations,
which will presently be stated.

It may, perhaps, be objected to the foregoing statements and
estimates, that the work was done in the long days of summer, and
in dry weather, when there would be the least obstruction to, or
loss of labour from bad weather and bad roads. And I will admit
further, that the expense incurred was not increased by sickness of
any one of the reg-ular marling hands, nor by any other important
loss in labour or materials. All these would be good grounds for
objection, if no allowances had been made for average losses on
these scores. But, in the general estimates of the cost of labour,
there were made the ample allowances of 30 days' labour of the
year lost on the average by each man and boy, by bad weather,
sickness, and half holidays (besides the 58 of Sundays and regular
holidays), and 40 days for each mule; and also enough for wear
and breakage of carts and utensils. Therefore the proper propor-
tion of these losses is in fact fully charged in the estimate, though
scarcely any of such losses occurred.

It is true that winter marling would be much more costly, owing
to the then generally muddy or slightly frozen and rough roads.
And therefore during that season, and when the earth is wet and
soft, it will be generally better to suspend marling labours, if the
teams can be employed at other, easier, and as necessary work. My
marling, however, was not thus suspended. For the extra expense
of the more disadvantageous and costly winter marling was deemed
of less amount than would be lost in the difference of productive
value of land marled, and the same if left unmarled. Thus it is
cheaper to pay $4 an acre, for marling a field before taking its crop
from it for that year, than to take the crop first^ and afterwards
29*

842 GRADUATED PITS.

marl it for ^2. And, therefore, deeming the omission or delay of
marling to he hy far the most expensive thing in regard to the
operation, I marled even in unsuitable seasons, so as to avoid the
necessity of ever again bearing the much heavier loss of cultivating
any unmarled ground.

Excavating Marl in large graduated pits

The excavation of the range of perpendicular pits C (Fig. II.),
was finished in April, 1845. The marl carried out from that and
the two previously worked ranges, A and B, amounted to 71,541
heaped bushels — according to the number of loads counted on the
fields, and their estimated quantities. Previous to beginning to
work at this digging, there had been carried out from another, not
far off, 26,600 bushels, from January 24th, 1844, to June 28th,
the time of beginning the second excavation. Of the earlier job,
it is enough to say that it was very laborious, owing to the overlay
to remove, of 7 to 8 feet, which was double the thickness of the
marl below. This, my first excavation here, was worked upon the
plan I had used elsewhere ; the carts descending by a gently graded
slope to the bottom of the marl. But every considerable rain caused
the loose sand and gravel to fall in and choke the small drain cut
around on the top of the marl, and then the spring and rain water
flooded the pit ; the bottom of the digging (when deep) being lower
than any outlet for the water. The many such disasters which
were suffered and repaired, and the consequent losses of time and
labour, induced me, for the next work, to pursue the more laborious,
but less hazardous plan of excavating by small perpendicular pits,
as described in the foregoing pages. But after thus working out
the ranges A, B, and C, I thought that with my then better expe-
rience, and by using better safeguards than before, I might venture
to return to the plan of graduated excavations. With this inten-
tion, the range D (Fig. II.), had been laid off, and cleared of its
overlay, during the winter and spring of 1845, at my leisure and
convenience, while the latter excavations of the range C were still
in progress. The same plan has been since continued, with im-
provements, for the successive and adjacent ranges, E, F, and Gr,
which last is not quite exhausted of its marl, at this time (October
1849), and another range, H, has nearly been cleared of its over-
lay, and made ready for its excavation to be begun. It will be
unnecessary to keep separate the incidents of these different large
workings, when referring to such processes as may be deemed worth
being mentioned. The natural features continued the same as to
the marl, and also of the overlay, excepting its increasing in thick-
ness, as the distance from the stream was extended. The different
means used for saving labour were mostly adopted in the working

REMOVING OVERLAY.

343

of the first graduated range, J), in 1845 ; but some of them were
introduced more recently.

The range B (Fig. II.), when completely uncovered and ready for
the carts to descend into, and to he loaded on the surface of the
marl, was 20 feet wide, including the space for the narrow drain
along its land-side (c, d, e, e,) for the greater part of its length —
narrower at the angle (^) and then widened to 26 feet at lower end,
to give room for a wagon to turn. The whole length was 255 feet ;
but of this, 96 at the upper end (c, d) had but half the overlay
removed at first; the earth being left in an inclined plane, sloping
downward from the road (gg) on the surface of tlie land, to
the surface of the uncovered marl. The thickness of the overlay
here having been 5 feet, the graded road served to rise that height
in 96 feet of the slope. The same grade was not exceeded in ex-
cavating the marl ; and it would have served to descend, if required,
two feet lower than the usual level of the bottom of the marl, at
the lower end of the digging. The digging and removal of the
marl was begun at the lower end (i, e, x) and carried on in succes-
sive layers ; but always keeping the floor of the pit sloping down-
ward towards the lowest end (x), and also laterally towards the
land-side (e, e). At the lower end was a short, narrow ditch
(e, X,) serving as an outlet into the stream, which had been deep-
ened so as to be lower than the lowest designed digging. Thus,
whatever water might get into the digging, from rain-floods, or
from the side-drain being choked by caving sand, and thereby turn-
ing in the spring-water, it would necessarily keep to the lower side,
and flow out at the lower end into the stream. The figures II., III.,
and IV., show severally the horizontal plan, and the longitudinal
and cross sections, or profiles of the work.

The first improved operation adopted was in removing the over-
l^J) ^y ^sing, where practicable and convenient, the plough to
loosen the earth, and the scraper (such as is used for road-making)
to move it into the finished ranges of pitting. The difibrence be-
tween these and the former modes of hand-labour, with hoes, picks,
and shovels, was not accurately observed, nor could it be ; as these
large operations were extended through several months (and more
lately, through a whole year), at such irregular times as labour
could be best spared, and especially when previous rain, snow, or
freezing had put a stop to usual farming operations. Any farmer
can nearly enough estimate the superiority of ploughing over hoe-
ing to loosen earth. The hoeing would certainly cost four times,
and perhaps ten times as much as ploughing. The scraper is also
very far cheaper than shovels, for removing earth to all distances
between 30 and 40 feet. For short distances, for which one throw
of the shovel is enough, the latter is the cheapest. The excavation
by plough and scraper was not only, as anticipated, much easier

Fig. III.

Longitudinal Section or Profile of Graduated Diggings (at
range D, in Fig. II.) Scale 40 feet to inch.

Explanations.

o, a, Surface of ground, and level of liigliest part of graded

roadway.
m, m, Overlying earth, 6 feet thick,
w, w, Marl, 7 to 8 feet thick.
8, s, Green-sand earth, of unknown thickness.
a, 0, r, Roadway, descending 6 feet in 96, from surface of

land a, to bottom of marl, r.
V, V, Vj Successive perpendicular excavations, beginning at r,

made after digging down to the inclined plane, o, r.
n, 0, Marl either excavated like v, v, or subsequently by a re-
. versed direction of descending grade.

« ^

o

Fig. IV.

Cross Section or Profile of Graduated Diggings (c
of range G, in Fig. II.) Scale 20 feet to inch.

Explanations.

a, a, Surface of ground (and overlay of next range
to be uncovered.)

d, d. Former extension of surface, now removed.

m, Overlying earth, here 7 feet thick.

n, Marl, 8 feet thick.

5, 5, 5, Green-sand earth.

O, The bed of marl, here removed from its original
height, the dotted line next above G i, to the line
below — and the lower part, w, t, still to be remo-
ved, to the bottom, at $.

t. Small drain, to intercept and lead off the springs
coming out of m.

t, Lowest graded side, or drain, to receive and dis-
charge accidental floods into the stream.

0, Wall of marl, left to be last dug out, to keep out
the water and earth from

g, p, k, Successive fillings of previous excavations, by
the overlay removed from the next uncovered.

(345)

346 EEMOVING OVERLAt;

where tlie overlay was dry and sandy, but also lower down in the
tv^et springy gravel, often indurated by ferruginous cement; and
even to some extent, in the wet, miry, and sticky clay still lower.
Difficult as was this lowest part of the uncovering, in every mode,
the scraper took up the clay, and let it drop because of the weight
of the mass, much better than any hand utensils. In this, the
plough was not needed, nor could the scraper be used much, because
the feet of the horses sank through both the miry clay and the
upper thin layer of soft marl (Fig. I.), and would have worked up
both together.

But the plough and scraper could not serve for all the overlay.
Not only for the miry clay layer, but for much of the other over-
lay, either because of its texture, or its place, it was still cheapest
to' remove by hand implements, as previously ; and especially for
giving the final shaping to the opening. If the job had been con-
tinuous and regular, and the labourers all able men, it would pro-
bably have been cheaper to remove the whole overlay at once in
wheel-barrows, in the manner of excavating for canals and railroads.
As it was executed, the saving of labour in removing the overlay
was fully one-half of the former cast.

To return to my actual labours. As soon as the wet gravel
(Fig. I.) was laid naked, the land-side outline of the range was
marked off, and a narrow ditch (c, cZ, e, e, x, Fig. II.) dug along
it down to the marl, intercepting the numerous small springs, and
conveying the water into the stream (at e, x, Fig. II.). After re»
maining thus drained for some weeks, the clay, though still miry
and sticky, is worked much more easily ; and in later operations,
has been mostly removed in carts, which were drawn upon the then
partly excavated and firm marl. The scrapers' work had pre-
viously served to fill the sinks and pools in the older ranges, with
dry sand and gravel ; forming a drained, firm, and nearly level sur-
face, on which the carts carried and dropped the remaining clay
overlay.

The design of the plan of operations vras to have the carts to
descend upon the marl, and to draw loads ultimately from the
lowest digging. For this purpose, as has been stated, part of the
overlay had been left on the upper end of the range (a, m, o, Fig.
III.), forming a sloping roadway for 96 feet of length, and rising
5 feet in that distance, from the marl to the road on the surface
of the land. A few yards of " poling'^ over the soft clay bottom
layer served to make a fitrm passage from the marl to the dry
Handy earth. The marl, except its upper 6 inches, was at first
firm enough for the loaded carts; and soon became dryer and firmer
in drying. The slope, given by the digging and removal of the
marl, descending always to one side and to the lower end, where
there was a discharging outlet into the stream for all water,

ADVANTAGES OF GRADUATED PITS. 347

served to keep the marl as dry as was possible for a naturally moist
and extremely absorbent bed. This preservation from all extra-
neous water, as well as losing some of its own by exposure, rendered
the m^arl easier to dig and to load, and something lighter of car-
riage.

Further — the digging was no longer impeded by the necessity
of having to leave, shape, and secure cross- walls, which had before
caused much trouble, and much loss of marl. Now there there was
but one wall to be left, which was along the whole length (o. Fig.
IV.), to keep out the earth and water which filled the old diggings ;
which wall was afterwards cut down, and mostly saved, in the
closing operations of each range, in succession. The unlimited
room for their work permitted the pit-men to dig the marl in much
larger masses, which saved much of the labour of digging, and
something in that of loading. For the earthy portion of this marl,
compact as it is, is composed of thin horizontal laminae, the result
of slow and uniform sedimentary deposition. In consequence, it
may be cleaved in the direction of its "grain" much more easily
than cut or fractured in any other direction. This facility is best
availed of when a wide area is worked; and not in small pits, con-
fined by perpendicular sides. The shovelling was also much easier —
first, because the marl was more in large lumps, and less in a finely
reduced state than before ; and secondly and mainly, because the
height of the cart was the greatest extent to which it had to be
thrown, instead of double throwing, as before, and the throw out
of the pit, which at the maximum, was 13 feet in height, besides
the lateral distance. This change, taking away all the throwing
out of the pit, saved much more than one-half of the pit labour.
The average quantity of marl obtained before from each pit-man's
daily labour was 148.42 bushels. Now, one man only was usually
employed, who dug for the carts from 400 to 600 bushels a day.
It is true, that he was now relieved from assisting to load, which
work was put upon the drivers. In the closing operations of the
digging, when small pits still had to be sunk, and through the
bottom stony layer, and the marl from them thrown up on the
sloping roadway, and walls to cut down, the result of the pit-man's
work was much less. But even then, when the difficulty was
greatest, the least amount of marl obtained was 160 bushels for
each man in the pit. It is certain, that throughout the whole ex-
cavation of the range, the pit-man's labour furnished on the ave-
rage more than twice the quantity of marl. This part of the cost
then also was reduced fully one-half. But this is in advance of
describing the later of the operations of which the cost was so re-
duced.

The digging down and removing the marl in the pit to the grade
of 5 to 6 feet depression in the 100 of length, served to reach the

845 MANNER OP EXCAVATION.

bottom green-earth, and leave it naked, for the extent of some 70 or
-80 feet length of the lower end of the range (r, in Fig. III.). This
completing of the excavation through the lowest marl was begun
-at the lower end, where is the outlet for water from the pit. . And
as soon as each successive few yards in length had been so deepened
to the bottom, the side-wall of marl was cut down, and its marl
mostly saved. Then, indeed, the earth, which this wall had been
left as a barrier to keep out, fell in, and more or less of the old con-
fined water beneath the earth flowed in also, from the old diggings.
But this now did no harm. The bottom (green-earth) where the
caving earth fell, and the water overflowed, was not needed ; and
the water, after rising a few inches thereupon^ passed ofl" through
the outlet into the stream. The next few yards length of bottom
marl was then removed, and then its part of the side-wall taken
down in like manner, until the whole lower 70 or 80 feet (z, r,
in Fig. III.) had been taken out, including its adjoining*side-wall.
Next, the lowest part of the sloping roadway of marl (/;, r, Fig.
III.) was dug out, the carts turning and loading on the adjoining
space next above, which also was next dug out. Thus, the whole
slope of marl was dug out in the manner of successive perpendicu-
lar pits (y, V, V, &c.), each of the full width of the range, and 6
or 8 feet in the direction of the range. The first or lowest of these
perpendicular diggings was not a foot deep at the upper side. Each
increased in thickness, until the last and highest (o. Fig. III.) at be-
ginning of the slope of the overlay forming the road, was 8 feet thick.
Still, though this digging was according to the former mode, by
perpendicular pits, this operation was much less laborious ; as the
throwing up of the marl varied in height from less than one foot,
to at most but 8. As fast as each of these pits was finished to the
bottom, the adjoining part of the side-wall (o. Fig. IV.) was cut
down, and as much saved as was not prevented by the coming in
of earth and water.

The thinner part of the overlay forming the slope (m, o, Fig.
III.) was next thrown, in successive uncoverings, into the last
finished pits, and the marl below in like manner dug out. But
when the thickness of this earth had reached some 3 feet, and about
50 feet of the length remained, this remnant was left to be taken
out with the next succeeding range of marl ; when carts, by having
a longer route, could descend on this part of the marl by a slope
made in a reverse direction (as space h o h, in ranges E and F,
Fig. II.) This postponement of the complete uncovering and the
digging out of the marl of the upper 50 feet of each range, for the
benefit of more easy access at a later time, has been since continued.
It is including all these more costly labours with the principal and
usual operation, that the excavation is deemed reduced in cost fully
one-half of that of the former mode.

CARTS AND TEAMS. 349

The labours of the teams and their drivers were slightly increased
by the change of plan. The carts had to be drawn from the bot-
tom of the digging, and also, for a large part of the time, frOm the
bottom of the bed of marl. But the ascent was so gradual, and
the way so-firm, that no greater effort was made necessary than
many of the obstructions on the nearly level ground, of roads or
field, encountered afterwards. The drivers also had now to put in
the whole of their loads, instead of being assisted by a pit-man, as
previously. But because of the greater distances in 1845, and
generally since, there were fewer trips, and of course fewer loads
to be put in and out, which kept- the loading labours to the drivers
nearly the same in general. These circumstances then added no-
thing to the former cost of hauling and loading.

Another gain was made in increasing the loads (by heaping
higher in the carts), from the heaviest of the preceding year to 9
bushels for the single-mule cart, and 18 bushels for the two-mule
carts. Of the latter, one was now regularly worked, and two others
frequently, and found to be much preferable. For if carrying a
double quantity, a two-mule cart was much cheaper than double
the price of a single-mule cart ; and also was cheaper in working,
than two small carts, in requiring one driver instead of two —
though a driver of more ability and value. The increase of loads
to 9 bushels to the mule (whether in single or double carts,) had
been made in April 1845, and has been maintained since, when-
ever the ground was firm, and the road good. Particularly, the
marling mules continued regularly to haul these loads through all
the time when so engaged that year, until in September, when
marling was suspended. They kept in excellent condition ; and
better than I have ever had the ploughing teams during summer.
The average day's travel, in hauling marl, had also been increased,
for weeks together, to as much as 26 miles ; and from April to
September was not less than an average of 2.5 miles. Any greater
distance was not desired ; but could not be always avoided, when
the trips were very long. The increasing the sizes of loads made
a diminution of cost, nearly equal to one-ninth, certainly to full
one-tenth of the previous cost of transportation.

The values of the several diminutions of cost of labour stated
above will be more clearly exhibited by comparative statement of
the expenses in 1844, before presented, and those of 1845.

30

850

COSTS OF ACTUAL MARLING LABOURS.

Total cost of applying marl, per 100 bushels, at the average dis-
■ tance of 1433 yards from pit to field ; or with 25 Tniles and
138 yards, of total daily travel.

In 1844.

In 1845.

Cts.
Labour of pit-man,

for 100 bushels . 26.00
Carting . . . .44.26
Tlirowing off overlay 13,00
Spreading marl . . 10.00

Total expense, cents, 93.26

Reduced by-
Half, or .
One-tenth
One-half .

13.00
4.42
6.50
0.

Leaves cost

Cents.

13.00

. 39.84
. 6.50
. 10.00

Total expense, cts. 69.34
Former cost . . 93.26

Reduction of ex. . 23.92

From all these detailed premises the conclusion has been reached
that, under the circumstances stated, or others not of greater difl&-
culty, the total cost of applying marl is less than 70 cents for the
hundred bushels — (69.34). The circumstances, and the elements
of cost, of course must vary with every locality, and even frequently
at the same locality. Nevertheless, the foregoing estimates and
results may be applied "to any other operations, with due allowances
for differences ; and thus may be facilitated the calculations of the
amounts and the costs of other marling operations.

From my large experience, not only of the years 1844 and 5,
but since to the present time, there can be no doubt of the ability
of carrying 1890 lbs. (18 bushels) of marl as the regular loading
of a two mule cart, on nearly level routes, and on firm ground and
good roads ; and that the regular and continued daily travel of
the carts, from pit to field loaded, and returning empty, may be
25 miles and 138 yards each day. Upon these grounds, it will
be easy to calculate the cost of marling at any greater or less dis^
tances than the average of mine (2867 yards from pit to field and
back) in the particularly noted trial in 1844. The transportation
is usually the main expense of marling. This, alone, increases
with and is in proportion to the distance; the other expenses are
not affected by the distance of carriage, but jemain in proportion
to the quantity of marl carried out, under like circumstances.
With the conditions last stated (for 1845, page 204), my expense
for carting alone of 100 bushels of marl, in trips to and fro of
2867 yards average distance, and making 25 miles and 138 yards
of total travel daily, amounted to 39.84 cents. All the other ex-
penses of applying the 100 bushels made 29.5 cents. These facts
furnish premises upon which to calculate what the total costs would
be for any other length of trips, as follows ;

COSTS AT DIFFERENT DISTANCES.

351

Bushels.
100

1
1

100

cost

Carting yards,
to and fro.

2867

2867

1760 (1 mile)

1760

Cents, for
carting.

39.84
0.3984
0.2446

24.46

and

Cents, for all
other labours.

29.5

+29.5
24.46

Total cost of 100 bushels, trips of 1 mile to and fro, 53.96

Upon these grounds the following table is constructed, showing
the cost of applying 100 bushels, for trips to and fro of all lengths
from 1 mile to 25 ; or of distances from pit to field of half the ex-
tent, or from half a mile to 12 ^^ miles; if there is no extra travel
to be included.

«!

Total cost of 100

Length of
trip to and

Costofcartingof 100
bushels.

Cost of all other labours.

bushels applied
at such lerigths

fro.

of travel.

(Cents.)

(Cents.)

(Cents.)

r Uncovering . . 6.5')

Miles.

} Pit work . . . 13. [-

(^ Spreading

. . 10. )

1

X24.46 = 24.46 ....

. 4-29.5 = 53.96

2

X24.46 = 48.92 . .

. 4-29.5 = 78.43

3

X24.46 = 73.38 . .

. -1-29.5 = 102.88

4

X24.46 = 97.84 . .

. +29.5 = 127.34

5

X24.46 = 122.30 . .

. +29.5 = 151.80

6

X24.46 = 146.76 . .

. +29.5 = 176.26

7

X24.46 = 171.22 . .

. +29.5 = 201.72

8

X24.46 = 195.68 . .

. +29.5 = 225.18

9

X24.46 = 220.14 .

. +29.5 = 249.64

10

X24.46 = 244.60 . ,

. +29.5 = 274.10

11

X24.46 = 269.06 .

. +29.5 = 298.56

12

X24.46 = 293.52 .

, +29.5 ^ 323.02

13

X24.46 = 317.98 .

. +29.5 = 347.48

14

X24.46 = 342.44 .

. +29.5 = 371.94

15

X24.46 = 366.90 .

. +29.5 = 396.40

16

X24.46 = 391.36 .

. +29.5 = 420.86

17

X24.46 = 415.82 .

. . +29.5 == 445.32

18

X24.46 =^ 440 28 .

. +29.5 = 469.78

19

X24.46 = 464.74 .

. . 4-29.5 = 494.24

20

X24.46 = 489.20 .

. . +29.5 = 518.70

21

X24,46 = 513.66 .

, . +29.5 = 543.16

22

X24.46 = 538.12 ,

. . +29.5 = 567.62

23

X24.46 = 562.58 .

, . 4-29.5 = 592.08

24

X24.46 = 587.04 .

. . +29.5 = 616.54

25

X24.46 = 611.50 .

. . +29.5 = 641.00

^[g^ RISKS OP GRADUATED PITS.

Thus it appears, that if 100 bushels of marl had been carted to
12 J miles distance from the pit (making the trip to and fro 25
miles), the cost of carting would be $6.11^-, which added to the
other fixed expenses, 29.5 cents, shows the total cost to be §6.41
th§ 100 bushels.

Superior in general advantage as is the mode of working of marl
in large graduated excavations, it is very hazardous in wet situa-
tions, without much care. The liability to damage is especially
great when the work of an unfinished excavation is suspended
through winter. Then the caving in of the side-walls, both of
overlay and of the marl, caused by frequent rain floods, and still
more by the frequent alternate freezing and thawing of the exposed
marl, may operate first to cho^e the passage, and soon to crumble
down the entire side-drain The outlet of water from the pit is
thus obstructed, and the quantity dammed up in the pit converts
the caved earth and marl to a mire. The successive freezing and
thawing continue to throw down successive layers of the walls,
serving still more to raise the water, and filling the pit with mire.
It has happened in my much earlier labours, elsewhere, that the
unfinished bottom of large spaces of marl was thus so covered in
deep mire, as to be given up, because not worth the great labour
of being again uncovered.

The surest safeguard against such dangers is to complete the ex-
cavations of each such large digging before freezing weather ; also
to throw in enough of the next overlying earth to cover the naked
upright wall of marl, and thus protect it from freezing. Then the
marl under the sloping roadways may be safely worked through
winter, in perpendicular pits, and each excavation, as soon as
finished, filled with earth, in uncovering another space of marl.

But when the extent of the range, or the insuflEiciency of the
force compels the large excavation to remain unfinished through a
winter, other means may be used, varying according to the features
of each locality, to prevent much loss, and which will be suggested
by the peculiar circumstances to the mind of every observing
marler.

In removing overlying earth, the excavation should not be
limited precisely to the laying naked a sufficient surface of marl,
and leaving the section of earth above nearly perpendicular. Even
if there is no likelihood of the earth so left caving down in masses,
and endangering the labourers below, the earth will be washed
down by every rain in small qantities; and crumbled down by
alternate freezing and thawing, if in winter. The face of the over-
lying earth should be cut to a slope (as seen in Fig. lY.) Then
if a layer is crumbled by freezing, or by drying, the loose
earth is kept in its place by its gravity. It is even cheaper, or

MARLING OPERATIONS AT MARLBOURNE. 353

more convenient, when removing tlie overlay by the plough and
scraper, to cut out as much beyond the outline of the designed un-
covering, as will give the slope of section recommended.

During 1846 and 1847, the next ranges, E and F (Fig. II.),
respectively of 22 and 25 feet width, and each increased in length,
were uncovered and excavated. The next range G was 33 feet
wide throughout, and 428 feet long. The excavation of the marl
of Gr was begun in January 1847, and was not entirely completed
by October 1849. At that tim'g there had been uncovered another
still longer range, H, 36 feet wide and about 450 long, which was
nearly ready, and could be so as soon as required to begin the
excavation of the marl. This last uncovering had been in progress
more than a year, having been worked at when most convenient to
spare, or to apply the labour. In each of the ranges since D, the
upper end of the marl, for 50 feet in length, had been left to be
taken out with the next succeeding range, for greater facility in
carting. Therefore so much of the range (x still remains in the bed.
[1849.] All the ranges excavated, omitting the unfinished part of
Gr (and all of H) and including the work at another earlier digging,
have furnished the following quantities of marl, as estimated by
the heaps counted on the fields.

Carried out
(I

in
((

((

1844,

1845,
1846,

heaped bushels,
a ((

<( a

67,875
75,512
35,546

a

(C

1847,

1848,

It

42,575
55,106

((

To Dec.

1849,
1850,

(parts of

(C

range H.)

66,169
34,684

Total 367,466 _

When my operations at this place ceased (December, 1850), there
then remained more than half of the marl of range H uncovered
and not excavated.
30*

CHAPTER XXX.

THE PROGRESS OP MARLING IN VIRGINIA.

My designed task is at last completed. Whether I shall be able
to persuade my countrymen to prize the treasures, and seize the
profits which are within their reach, or whether my testimony and
arguments shall be fruitless, soon or late a time must arrive when
my expectations will be realized. The use of calcareous manures
is destined to change a large portion of the soil of lower Virginia
from barrenness to fertility ; which, added to the advantages we
already possess — our navigable waters and convenient markets, the
facility of tilling our lands, and the choice of crops offered by our
climate — will all concur to increase ten-fold the present value of
our land, and produce more farming profit than has been found
elsewhere on soils far more favoured by nature. Population, wealth
and learning, will keep pace with the improvement of the soil ; and
we or our children will have reason to rejoice, not only as farmers,
but as Virginians, and as patriots. [1832.]
* Such, as appear in the last paragraph, were the concluding words
of this essay, as published in 1832, and substantially as the work
had been prepared for the press six years before that publication
was made. Such was then the language of hope and anticipation.
It may now [1842] be both interesting and useful to examine to
what extent such hopes and sanguine anticipations have been so far
realized.

Every new and great improvement in agriculture has had to
work its way slowly and in opposition to every possible discourage-
ment and obstacle. It would seem that the agricultural classes are,
of all classes and professions, always the least ready to receive
benefit from instruction — the most distrustful of instructers, and
the least thankful for their services — even after the benefit is the
most completely proved, and established by actual practice and un-
questionable facts. The novel improvement by marling has not
presented an exception to this universal rule. But still, it may
be confidently asserted, that no other agricultural imjjrovement has
been so raindly extended, so widely and generally received in such
short time, or has been so generally and greatly jiro^table to all
who have availed themselves of the benefits thereby offered to their
acceptance. When my fii-st trials were made in 1818, so far as I
then kneW; I had no forerunner in success. For the few and small

' (354)

EARLY OBSTACLES TO MARLING. 855

and long abandoned experiments, then known, and the opinions
deduced therefrom, stood as warnings against, and not in the least
as encouragements to repetition ; and the then actually proceeding
use of marl, silent and unknown, and to small extent but successful,
had not even been heard of. A few more years served to dispel
all doubts of those who had tried or could witness the results of the
applications of marl. Still, ignorance of the mode of operation has
not been dispelled by the knowledge of the great benefits of marl ;
and therefore the grossest errors of practice accompanied and greatly
lessened the full advantages of the continually extending use of
marl. It required but little time for all to learn and assent to the
propriety of the one main and simple instruction, " apply marl -/'
but few would consent to learn anything else ; or would believe that
there was anything else necessary to learn or to do, except merely
to " apply marl." They would not learn from anything but their
own dearly bought experience of error. And very many have thus
learned, and have paid the cost to their own pecuniary loss of thou-
sands of dollars in value — whether in delay by misapplied effort, or
in positive loss and injury sustained by wrong practice — which the
outlay of a few dimes, and the attentive reading for a few hours,
might have effectually guarded them against. And so it still goes
on, and will go on, with all who are new beginners and learners,
and who have not yet paid each their hundreds or thousands of
dollars in loss, in preference to less than as many cents, in both
money and labour, in acquiring proper instruction, and security
from all such loss.

But with, all such enormous drawbacks of loss, which if avoided
would have doubled the actually achieved benefits, the extension
of marling and liming, and the amount of benefit thence derived
and realized in lower Virginia, since 1818, have had no precedent
in the annals of agricultural improvement by any mode of manuring.
The following extract from a more general report, recently made by
the writer to the State Board of Agriculture (in 1842), will present
this branch of the subject in its proper aspect.

" Marling, or manuring from beds of fossil shells. — This mode of fertiliza-
tion, now so general through all the marl region of lower Virginia, was not
practised except on three or four detached farms, and that to but small ex-
tent before 1820. Some few and small experimental applications of marl
had indeed been made by different individuals, from 15 to as far back as
45 years earlier ; but which applications, from total misconception of the
true mode of action of calcareous manures, had been deemed failures ;
and, without exception, had been abandoned by the experimenters as
worthless; and the experiments had been almost forgotten, until again
brought to notice, after and in consequence of the much later and fully
successful introduction of the practice.

" Henley Taylor and Archer Hankins, two plain and illiterate fanners,
and near neighbours in James City county, were the earliest successful and

Ifi^ EARLIEST MARLING OPERATIONS.

continuing appliers of marl in Virginia. But at what time they began, and
■which of them was the first, I have not been able to learn ; though visiting
Mr. Hankins' farm for that purpose, as well as to see his marling, and
making inquiries of him personally, in 1833. Mr. Taylor had then been
long dead, and his improvements said to be almost lost, by the exhausting
tillage of the then occupant of his land. ^Mr. Hankins was unable to say
when he and his neighbour began to try marl. He was only certain that it
was before 1816. Yet, though these farms are within 12 or 15 miles of
Williamsburg, to which place I had made visits once a year or oftener, yet
I never heard an intimation of their having begun such practice, until some
time after my own first trials in 1818. At that time, when led to the use,
as I was, altogether by theoretical views, and by reasoning (in advance) on
the supposed constitution of the soil, as well as the known constitution of
the manure, it would have been to me the most acceptable and beneficial
information to have heard that any other person had already proved prac-
tically the value of marling. The slow progress of the knowledge of the
mere fact of marl having been successfully used before that time, was a
strong illustration of the then almost total want of communication among
farmers, as well as of their general apathy and ignorance in regard to the
means of improving their lands.*

" Much earlier than the commencement of marling in James City, the
practice had been commenced (in 1805), in Talbot county, Maryland, by
Mr. Singleton. His account of his practice is in the 4th volume of the
' Memoirs of the Philadelphia Agricultural Society,' dated December^l,
1817, and first published some time in 1818. But successful as was his
practice, and also that of Mr. Taylor and Mr. Hankins in connexion with
much worse farming, it is certain that neither of these individuals had the
least idea of the true action of marl ; and they were indebted to their good
fortune, more than to any exercise of reasoning, that they received profit-
aj^le returns, and did no injury by marling. - They all three applied their^
putrescent manures with the marl. But though this was the safest and
most beneficial plan, the thus uniting them prevented the separate action
and value of putrescent and calcareous manures being known, compared,
and duly appreciated.

" My own application of marl, on Coggins Point farm, Prince George
county, which in 1818 extended only to 15 acres (of which but 3 or 4 were
under the crop of that year), by 1821 had been increased to above 80 acres
a year, and so continued until nearly all the then arable land on that farm
requiring it (more than 600 acres), had been covered. In 1821, my earliest
publication on the subject was made. Though the facts and reasoning thus
made known by that time were beginning to attract much notice, and to
induce many persons to begin to marl, still it was some years later before
incredulity and ridicule had generally given place to full confidence in the
value of the improvement. Even at this time, when nearly 25 years of my
own experience of marling and its benefits have passed, and the results are
open to public notice and scrutiny, half the persons who could marl are
either not engaged at it, or are marling to but little purpose ; and of all
who are using marl, nineteen in twenty are proceeding injudiciously, with-
out regard to the mode of operation of the manure, and therefore are either
doing harm, or losing profit, almost as often, though in less degree, as
doing good. At this time, however, there are scarcely any persons, how-
ever negligent or mistaken in practice, who do not fully admit the great
value and certain profit of applying marl, wherever it is available.

•— ■^

* See a more full account at page 108, vol. i., Fanners' Register^ ^^^,

PROaRESS OF MARLING. S57

"But with all the existing neglect of using this means of fertilization,
and with all the still worse ignorance of or inattention to its manner of
operating, there never has been a new improvement in agriculture more
rapidly extended, or with such beneficial and profitable results. In Prince
George county there is not one farmer having marl on or near his land,
who has not applied it to greater or less extent, and always with more ot
less profit — and, in most cases, largely as well as profitably. In James
City county there has been perhaps the next largest as well as the oldest
practice. In York county, as in James City, some of the most valuable
and profitable improvements- by marling have been made. And some of
the farms of both counties, adjoining Williamsburg, and having the benefit
of putrescent town manures, show, more strikingly than any others known,
the remarkable power of calcareous manure to fix the putrescent in the
soil, and make them more efiicient and far more durable. In Surry, Isle
of Wight, Nansemond, Charles City, New Kent, Hanover, King William,
King and Queen, Gloucester, and Middlesex counties, in the middle of the
marl region of Virginia, marl has been already extensively applied, and the
profits therefrom are annually increasing. And in other surrounding coun-
ties, less abundantly supplied with marl, the practice has been carried on
in proportion to the facilities, and to the more scanty experience and degree
of information on the subject. It would be a most important statistical
fact, if it could be ascertained how much land in Virginia^ has already been
marled. The quantity however is very great ; and all the land marled has
been thereby increased in net product, on the general average, fully 8
bushels of corn or oats, or 4 bushels of wheat, if following corn, and the
land increased in intrinsic value fully 200 per cent, on its previous value
or market price. Where the marling has been judiciously conducted, these
rates of increase have been more than doubled. From these data, might
be calculated something like the already prodigiously increased values
and products due solely to marling, and which will be still more in-
creasing from year to year. If not already reached, the result will soon be
reached, of new value to the amount of millions of dollars having been thus
created. * * * * *

" It required the improvement by marling, on originally poor and mid-
dling soils (or liming, which in final or general results is the same thing),
to render as generally available the best (and otherwise but rarely found)
benefits of the two kinds of vegetable manuring recommended by Taylor*
When such soils have been made calcareous, by marling or liming, then,
and not until then, all the benefits, presenjb and -future, that his readers
might have been induced to expect, may be confidently counted upon. In
my own earlier practice — and Taylor had no greater admirer, or more im-
plicit follower — I found my farm-yard manurings on acid soils scarcely td
pay the expense of application, and to leave no trace of the effect after a
very short time. And land, allowed to receive for its support all its vege-
table growth (of weeds and natural grass) of two and a half years in every
four, and the products in corn having been measured and compared, showed
no certain increase in more than twenty years of such mild treatment.
Since, on the same fields, farm-yard manures, in every mode of prepara-
tion and application, always tell well, both in early effect and in duration.
And even the leaves raked up on wood-land, spread immediately and with-
out any preparation as top-dressing on clover, always produce most mani-
fest improvement, and are believed to give more net profit than any appli-
cation of the much richer farm-yard manure, per acre, made on like land
before it is marled. This utilizing and fixing of other manures, and the
fitting land to produce clover (and to receive benefit from gypsum on clo-

358 PROGRESS OP LIMINO*

Ter), -wliicli effects of marling are in addition to all the direct benefit pro-
duced, woiild alone serve to give a new face to the agriculture of the
country. Whatever may be done by clover, and almost every thing that
can be done to profit by vegetable manures, on the much larger propor-
tion of the lands of lower Virgina, will be due to the application of marl
or lime.

" Liming. — The kindred improvement by liming began to be extensively
practised on some of the best James river lands, where no marl was found.
Boon after the use of the latter began to extend. Who may have made
the earliest and small applications of lime is not known, nor is it at all im-
portant. The earlier profitable use of lime in Pennsylvania, and the much
earlier and more extended use in Britain, were known to every well in-
formed or reading farmer. Such a one was Fielding Lewis, of Charles City,
as well as a most attentive, judicious, and successful practical cultivator
and improver. He is believed to have been the earliest considerable limer,
and the one who obtained the most manifest profits therefrom, and whose
example had most effect in spreading the practice. Some of his disciples
and followers have since, in greater rapidity and wider extent of opera-
tions, far surpassed their teacher and leader — to whom, however, they
award the highest meed of praise for bringing into use, and establishing,
this great benefit to the agriculture of lower Virginia. Nearly all the best
soils on James river are comparatively of low level, as if of ancient alluvial
formation, and have no marl, with which the neighbouring higher and
poorer lands are mostly supplied. Of such rich lands are the farms of Wey-
anoke, Sandy Point, Westover, and Shirley, &c., in Charles City, and
Brandon (Upper and Lower), in Prince George — and on all these lands, as
well as some others, lime has been largely applied. The use is extending
to the lands on and near to all the tide-waters of the state ; and it has re-
cently I'eceived a new impulse from the low price at which northern stone-
lime is now brought and sold. It is ready slaked, and the vessels are
loaded in bulk. The lime is sold on James river at 10 cents the bushel,
and even may be contracted for at 8 cents, from vessels that come for car-
goes of wood, and would come empty but for bringing lime. The greater
lightness and cheaper transportation of lime will enable it to be applied
where marl could not be carried with profit ; and with the two, there will
be but little of lower Virginia which may not be profitably improved by
calcareous manures."*

With all the caution proper to be used in a report made to a
Board of Agriculture, and through it to the government of the
commonwealth, the writer dared to predict, in 1842 (as quoted
above), of the increased value of lands caused by marling, that ^' if
not already reached, the result will soon be reached, of new value
to the amount of millions of dollars having been thus created.''
Because of the then deficiency of statistical and documentary
evidence (since partially and imperfectly supplied), he was not
then aware that this prediction had already been more than fulfilled.

* Extract from *' Report to the State Board of Agriculture, on the most
important improvements of agriculture in lower Virginia, and the most
important defects yet remaining." Published by order of the General
Assembly, as a state document, and also in Farmers' Register, p. 257,
vol. X.

ErFECTS ON PUBLIC INTERESTS. 859

The message of the present Grovernor of Virginia to the legislature,
in January, 1852, stated, upon the evidence of official documents,
that the assessed values of lands in the tide-water district, had been
increased more than 17 millions of dollars in the twelve years pre-
ceding the last assessment of 1850. The governor properly ascribed
this increased value of lands of this region to the recent fertilization
of particular portions. With all well-informed residents, or those
acquainted generally with the past and present circumstances of
this region, there will be no question as to the ichole of the in-
creased value being due to the use of calcareous manures. For
before the introduction of this still recent practice, both the intrinsic
and the market values of lands had decreased — as they have con-
tinued since to decrease in the neighbouring counties in which
there has been very little or no use of marl or lime. All other
improvements of agricultural practices, great as they certainly have
been, have not sufficed to replace the productive power wasted by
the generally exhausting tillage.

But great as is this declared general increase of value of the
lands of this tide-water region alone — and, as I maintain, from the
effects of calxing alone — it is not near so much as can be truly
asserted, and satisfactorily proved from the public documents and
statistical tables, defective as they are for this course of investiga-
tion. This is not the place to offer in detail the authorities and
proofs of these important facts. But this shall be done in another
paper, which will be a communication to the State Agricultural
Society. In that paper I will maintain, and expect to establish,
the following propositions, of which the enunciation will be here
stated concisely, in advance of the proofs, and deductions therefrom,
which will hereafter appear :

1. The parts of lower Virginia, long settled and cultivated, and
also the neighbouring upper counties, bad been decreasing in pro-
duction, in population, and especially in productive or labouring
population, in wealth .generally, in the intrinsic or productive value,
and also the selling and assessed values of lands, for more or less
time, previous to the commencement of the improvement by marl-
ing; and such decrease has continued to this time, and is still pro-
ceeding, wherever there has been no marling or liming.

2. In the counties in which most land has been improved by
marling or liming, and only since these improvements were in pro-
gress, there has been a marked change from the former declining
condition, just stated, to increase of value of lands, of wealth gene-
rally, and of products of taxation — and as a later and as yet less
advanced effect, an increase of population also.

3. This change from decrease to increase of the values of lands,
though not indicated by official documents earlier than the assess-
ment of 1838, (there having been no previous assessment later than

860 ErFECTS ON PUBLIC INTERESTS.

tliat of 1819), had in fact begun about 1828, when there existed a
much lower state of depression of production and of value; from
which lower rate, and earlier time, the selling value of lands, and
much more the productive or intrinsic value, had been increasing
for 22 years preceding the last assessment of 1850 — and (at least)
to the amount of nearly 30 millions of dollars; instead of 17i
millions increase in 12 years, as computed in the governor's mes-
sage.

4. All this stated increase of value of lands is much less than is
the actual increase ; and though stated as for the whole tide-water
district, in truth it has been achieved upon a very small proportion
of the surface of that district — the great remainder (more than
twenty times as much in quantity) — still being without any such
improvement, or increase of either assessed or productive value.
Even on the very small proportion marled or limed, the improve-
ments are of loss than half the value which judicious procedure
would have effected, and earlier, at less cost, and also permanently.
Hence, the actual calxings may yet be doubled in effect and value,
and twenty times as much space may be raised to like increased
production and value.

5. Therefore, the admitted newly created value of land, of 17i
millions of dollars between the two latest assessments, and the as-
serted increase of nearly 30 millions from 1828, are both, beyond
comparison, far below the available increase for the whole of the
tide-water district alone — to say nothing of the other parts of Vir-
ginia, improvable by like means. The whole available increase
of value on lands alone, and for the tide-water district alone, on the
premises stated, may reach to 500 millions of dollars — with pro-
portional increase of value of other farming capital and connected
movable property, and of population and products of taxation.

Enormous or incredible as these predicted results may appear, I
maintain that there is more ground now to expect the complete
fulfilment within the next' 35 years, than there was, 35 years past,
in the then desperate condition of agriculture, to expect, not only
the now actual increase of values in lower Virginia, but even any
smaller general increase. The main thing needed to aid and hasten
the fdfilment should be a measure which heretofore has been en-
tirely neglected and scornfully refused, in this and in all other
relations to agriculture, viz. : that the government of Virginia
shall in proper manner induce investigation, and encourage the
diffusion of knowledge, in this and every other department of agri-
cultural research and labour.

In the report, part of which was quoted above, it was recom-
mended, and again more formally in the general report of the Board
of Agriculture -to the legislature, that the amount of land marled
and limed should be obtained by the commissioners of the revenue,

NEGLECT BY THE GOVERNMENT. 861

and reported by the government. This small and costless aid to
agricultural knowledge, and encouragement to further improvement
(as well as all aid of greater value), the legislature of Virginia denied.
If it had been granted, and thereby had been shown the real extent
of these improvements in every county, and even as it might be on
every farm, these facts, in connexion with the values shown by the
different assessments, would have exhibited clearly and fully the
results which can now only be inferred generally, loosely, and ac-
companied necessarily by many errors. Such important results,
so fully established, and made so obvious to all, would have operated
more strongly than any and all other existing incitements, to en-
courage the extension and the judicious procedure of improvements
by calcareous manures. It would then clearly appear which in-
dividuals had secured to themselves this 30 millions of dollars of
already increased value of property, and by what easy means. And
all other persons, who could follow the example, and secure their
shares of as rich rewards, would be imperatively called to use the
like procedure, and so obtain the like benefit for themselves and
for the commonwealth. It would have been to the before and still
listless and inert proprietors and cultivators of our poor and unim-
proved lands similar in effect with the first announcement of the
gold of California being ready for every needy adventurer who
was able to go and dig for it. In the use of calcareous manures, on
all the poor or exhausted land where their use is available, there
are offered rewards to all judicious adventurers far richer, and more
certainly and largely productive, than the golden products of Cali-
fornia— and the former would be as much conducive to pilblic and
private weal, as the gold of California has been and will be in-
jurious to both.

31

APPENDIX

INTRODUCTORY REMARKS.

In the foregoing exposition of theory and practice, it has been
the object and effort of the author to embrace whatever seemed
necessary for proof or for illustration ; and to omit everything else,
lest too much of amplification or digression should weaken rather
than strengthen the main positions. Thus it is believed that the
foregoing chapters, as argument and proof, serve to establish the
series of propositions which were at first advanced and throughout
contended for. Still there remained many minor but interesting
subjects, more or less intimately connected with the investigation,
or serving for more full proof, and which well deserved more ex-
tended discussion, and the consideration of those readers who should
desire to pursue farther the general object of this essay. These
subjects will be treated separately in the different articles of this
appendix ; which may be read, it is believed, with both interest and
benefit by the more inquiring class of readers ; or may be passed
over, by the more cursory and careless, without much detriment to
the arguments and facts of the preceding portion and regular body
of the work.

NOTE I. — Extension of the subject or pages 92 — 97. '

Additional proof J offered in t%e production and existence of hlach
waters^ of the action of lime in combining vegetable matters with
soil.

Every person who has seen much of the different parts of lower
Virginia (to go no farther for examples), must have remarked the
dark permanent colour of the waters' of many streams and mill-
ponds ; and that others, whether when clear or when turbid, are at
all times and entirely without any tinge of this peculiar colouring
matter. The waters thus coloured by vegetable matter are more
deeply tinted at some times than at others ; but are always strongly

363

364 BLACK WATERS.

thus marked. Tliese waters, when several feet in depth, appear to the
eye quite black or very dark brown. The same if viewed in a drink-
ing glass would appear of the colour of Sherry wine, and might
present some shade between the palest and deepest tints of such
wine. This colour has nothing of muddiness; for these waters are
as clear from suspended clay or mud as any other waters not so
coloured in the slightest degree. In the county in which nearly
all my life has been passed. Prince George, these different kinds of
waters are to be seen in stronger conti-ast, because of their close
neighbourhood. All the streams which flow into Blackwater river^
as well as the main stream which that name so well describes,
from its head to its outlet, are coloured deeply, and it is believed
without exception. On the contrary, the streams which flow into
James river are all without the least tint of colour, though they
often rise from sources very near to some of the others, the head-
springs being on opposite sides of the same dividing ridge of level
tiable land, and in lands precisely alike. Some of these lands are
of close and stiff soil, and some more sandy and quite light j but
all are level, poor, and acid lands, and are mostly still under forest
growth.

All persons, whether of the most or the least observant class,,
would concur in the opinion that this colour proceeds from vegeta-
ble matter. This is obvious even in the waters of heavy rains,,
which when more than the level ridge lands can absorb, flow off^
and are sometimes for a day or more thus passing in temporary
streams to the nearest valley, or other descent. These surplus
waters, while yet on the highest woodland, are coloured to a greater
or less depth of tint; and just as much in those which take their
course towards James river, as the others which flow in the opposite
direction to the Blackwater. The difference is that the former soon
lose all such colouring matter, and in no case carry it to or even
near James river, whilst the other waters increase in depth of
colomr with the length of their course, or the duration of tim^ they
remain in the mill-ponds they pass through, or in the sluggish Black-
water river.

The supply of colouring matter is principally furnished by the
dead and fallen leaves in the poor forest land, and is doubtless in-
creased afterwards, both by the partial evaporation of the water,
and by its dissolving still more of the soluble vegetable extract in
the flat swampy grounds through which the streams flow into the
Blackwater. This might indeed' satisfactorily account for these
waters being more deeply coloured than those which pass by a more
rapid descent to James river. But these different circumstances
do not serve at all to explain why the latter waters should soon
lose, if they had it at first, the slightest trace of colour.

The like circumstances are probably to be found to more or less

BLACK WATERS. 365

Extent in most of the counties on our tide-water rivers, as most of
them have poor forest lands and some swampy streams in the
interior.

As the opposite circumstances of the presence or absence of
colour in different waters is certainl}' not caused by such difference
in the sources of supply, they must be caused by some subsequent
action, which serves to clear the waters in one locality, by combin-
ing with and taking off the dissolved colouring matter, and which
action does not take place elsewhere, because there is no such
efficient agent present. That agent I take to be carbonate of lime,
or some other salt of lime in the soil in the one case, and which is
present in quantity altogether insufficient for such action in the
other case. According to the views which were presented (page
96) in regard to the power of calcareous earth to combine chemi-
cally with vegetable matter, if the coloured waters should flow over
soils furnished with calcareous matter, or into streams impregnated
with any salts of lime, it would follow that the suspended or dis-
solved vegetable extract would combine with the calcareous matter
of the soil in the water, and the new combination be precipitated,
and be given to the soil, as manure, either immediately or remotely.
This effect would be greatly aided if the streams swollen by rains
actually passed in contact with and washed away exposed banks of
marl. All recent rain-water contains a small amount of carbonic
acid, and that impregnation enables water to dissolve a proportional
quantity of carbonate of lime, which is insoluble in water without
this addition of carbonic acid. Therefore, in such circumstances
the swollen streams and land floods would necessarily dissolve some
carbonate of lime, which would be thus placed iramediat*ely and
fully in mixture and perfect contact with the before dissolved vege-
table colouring matter, and next must take place the combination
of the two, and precipitation of the compound manure. The con-
sequence must be, that the lands thus overflowed must be more or
less enriched by every heavy rain ; while the lands overflow(?d by
the coloured waters receive, or retain, nothing of soluble vegetable
matter from this source, and may even lose part of what they had
before received from the decay of their own growth, or other
sources, by its being dissolved and carried off by such overflowing
waters.

Now let us see how the actual results agree with these different
causes, so far as the causes are known to exist. In the limited
region particularly referred to above, the low grounds, subjAt to
inundation by rains in a state of nature, and having beds of marl
which the stream cuts through, are of much richer soil than any
others, though the quantity of marl displaced by the stream (if in-
deed any such displacing be perceptible) would seem altogether too
small in amount to produce such extent of fertilization by direct
31*

§68 CLEARNESS OF LIME-STONE WATERS.

action. And it is believed, whether marl beds be so exposed or
not, that the low grounds on the streams of colourless water are
always much better soils, and of more durable fertility, than those
•washed by coloured waters. The latter soils being often swampy,
are full of vegetable matter, and of course would be very productive
when first drained and cultivated. But these soils are far from
being among the most durable, and they are even at first, and when
in best condition, very inferior lands to most low grounds of prime
quality; and the latter are always penetrated by streams, or had
been sometimes covered by floods, which, however turbid at certain
times with suspended clay and mud, are never coloured by vegeta-
ble extractive or soluble matter alone.

If we go farther for examples, the efi"ects will be found to be
still more striking. None of the lime-stone streams are ever
coloured ; and their remarkable transparency, very far surpassing
that of the most pure and limpid waters of the low country, show
that the dissolved lime, which the mountain streams contain, serves
to remove everything of colouring matter. These lime-stone wa-
ters, and land floods from rains which also necessarily carry dis-
solved carbonate of lime, form the principal supply of the upper
James river. But long before the waters reach the head of tide,
not a particle of lime remains. The dissolved lime had been con-
tinually uniting with the suspended or dissolved vegetable matter,
until no lime was left, and the precipitated compound had served
to add more manure to the extensive low-grounds along the whole
course of the upper James river, and which are so well known and
deservedly celebrated for their great and enduring fertility and
high value.

When a resident of the lower country first visits our mountain
and lime-stone region, he cannot avoid observing and being forcibly
impressed by the remarkable clearness of the waters. Pools and
basins in the streams containing six feet depth of water, will ap-
pear'to his unpractised eye as not deeper than two or three feet.
And it is only by comparison, and by becoming acquainted with
this really and perfectly clear lime-stone water, be learns that ho
had, in truth, never before seen a stream or pond of perfectly clear
water. Though the dissolved matters may be in too small quan-
tity to produce any appearance of colour, they serve to impair the
transparency of the water. And when any such colouring or
vegetable matters are received into and intermixed with lime-stone
stre#ias, the vegetable matter is immediately combined with lime,
and the compound precipitated ; still leaving in the water a great
excess of dissolved lime, scarcely diminished by the loss of the
small part acting to clear the water of all colouring and vegetable
impregnation.

From the large proportion of lime held in solution by lime-stono

LIME-STONE \^ATERS. 367

springs, and the streams proceeding from them, and also by rain
floods passing over lime-stone soils, it must be inferred (according
to my views), that such waters must very quickly combine with
and precipitate all colouring matters, and, when not turbid with
earthy matter, be as transparent as water can possibly be. Hence,
the well known and remarkable transparency of such water is not
directly caused (as commonly understood) by lime being contained
in them — but because of the other adulterations being totally re-
moved in combination with a part of that dissolved lime. Thus,
the water is not in the least made crystalline and transparent be-
cause of what it contains, but because of what it has been deprived
of. And, therefore, even after all the lime may have been pre-
cipitated, the water must retain its previous perfect transparency,
unless subsequently impregnated with other colouring matter.

The additional supply of carbonic acid to water, which alone
gives to it the power to dissolve or to retain in solution even the
smallest proportion of carbonate of lime, is not strongly held. It
is given off by the lime-stone water in its partial evaporation, and
to every contact of atmospheric air j and this operation is increased
by such agitation of the water as exposes a larger surface to the
air. Hence, at all rapids of lime-stone streams, there is a pecu-
liarly rapid and large deposition of carbonate of lime, let loose by
the water because of the loss of the proportion of carbonic acid
which before served to hold the lime dissolved in the water. This
precipitation and gradual accumulation of carbonate of lime, at the
rapids and cascades of streams, is the formation called calcareous
tufa or travertine, and vulgarly called '^marF^ in our mountain
region, and which is presented in great quantity, and sometimes in
enormous masses.

As lime-stone water so easily parts with the carbonic acid which
enables it to hold lime in solution, it can scarcely be supposed that
any of the acid remains after the water collects and remains long
in the great reservoirs formed in lakes. But whether the water
remains impregnated with carbonic acid, and of cou]?se with lime,
or has lost both, the effect is the same, and is exhibited most
strongly in the remarkable transparency of lakes so formed. Of
such, I have never myself witnessed any but of Lake George, in-
New York. And after the long lapse of time since my short visit
to this lake, I cannot remember to what extent the transparency
of its waters was asserted, or what my own personal observation
ascertained. I only remember certainly that the depth of water
through which very small objects were distinctly visible was very
great, and that no ground was left to doubt what is generally-
asserted and received as true on that head.

To return to the lands and waters of Prince George county.
The water left by heavy rains, standing in shallow pools on the

868 BLACK WATERS.

higli level wood-land, and flowing off" in temporary rivnlets, is seen
to be coloured by vegetable matter even within a mile of James
river, just as it is found on the other lands sloping towards the
Blackwater. But in either and every known case of such dis-
coloration being caused, it is on poor and acid land. No such
effect takes place on calcareous or even neutral soil, no matter how
abundantly it is provided with dead leaves or other vegetable mat-
ter. Therefore it is jnanifest that it is not difference of locality,
but difference of soil, which causes the different effects of the
surplus "rain-water becoming tinged, and remaining tinged with
vegetable extract, or otherwise remaining colourless. And also,
after the water has been so tinged, that it depends on the difference
of chemical composition in the soils over which it passes, or of the
streams into which it is discharged, whether the colour remains or
is quickly discharged. And, as already stated, this difference of
action and effect depends on the absence or presence of lime in the
soils or waters to which the coloured excess of rain-water flows.

It is only in the surplus quantity of rain-water, or that which is
more than the soil can absorb, that this colouring matter is seen.
But it is not the less certain that all of the much greater quantity
of water from more gentle and more frequent rains which soak
into the earth, must also be more or less tinged with the colouring
matter of the leaves and other dead vegetable matter through
which the water passes, and must take up, in passing, all that is
then easily soluble, and not chemically combined with some other
body. Thus, every gentle and soaking rain probably carries into
the soil the greater part of all the then soluble vegetable matter,
and that only which is soluble is all that is then completely ready
to act as food for plants. The same rain, and the subsequent
chemical action of air and warmth, cause the decomposition of the
before insoluble vegetable matter to recommence, and in a few
days there is a renewed supply of soluble or extractive matter
formed in the vegetable cover of the soil, ready to be dissolved and
to be carried into the earth by the next succeeding rain.

Such is nature's process of furnishing alimentary manure, or
the food of plants, to soils. And the source of supply is unlimit-
ed ; for it is principally from the atmosphere and water, and by
fixing their elements (oxygen, nitrogen, hydrogen, and carbon), that
the vegetable growths of soils, and consequently all alimentary
manures, are formed.

Enormous then as is the continual waste of vegetable ex-
tractive matter and manure that is caused by every heavy rain, and
wEich is always evident to the eye in the black waters of so many
ponds and streams, all this lost fertilizing matter m*ist be in very
small proportion, compared to the greater quantity that is -carried
more gradually and frequently into the earth. Much the greater

BLACK WATERS. 369

part of the wood-land of lower Virginia is most freely and abund-
antly thus supplied, not only because of the abundant sources pre-
sented in a thick layer of fallen leaves, the growth of many
successive years, but also because of the very level surface of the
land, which obstructs the flowing off of the surplus rain-water, and
the general sandy and open texture of the soil and sub-soil, which
operate to absorb quickly the water and its dissolved vegetable
matter. Yet it is more especially these lands that show the least
remaining and abiding store of this supply of vegetable manure.
The soil, or all of the upper part which shows any colour from
containing vegetable matter, is usually not more than two inches
thick on sandv soils, and still less on the stiffest ; and all the por-
tion below (though necessarily manured by being often soaked to
a foot or more with rain-water conveying all its dissolved vegeta-
ble extract), is entirely barren and worthless. Such results would
be as inexplicable as they are wonderful, but for the reasons afford-
ed by the doctrine of the combining and fixing powers of carbonate
of lime and vegetable salts of lime; the absence of which ingre-
dients is the sole defect in these cases, and which, when present in
soils, show results of fertilization altogether the reverse of these.
Where lime is present in sufl&cient quantity, no colouring or ma-
nuring matter is lost to the soil in the flowing off of surplus water,
nor in the wasteful and profitless decomposition of the greater
T^uantity of colouring and alimentary matter soaked into the earth.

My observation was not attracted to the cause of the existence
of black waters, and this application of the facts, until nearly the
close of my residence in the country, and of my opportunities for
personal and accurate observation. And I am well aware, and
ready to admit, that previous observations, made by mere chance
and without object, are worth very little comparatively. I there-
fore would be glad to have the attention of other observers drawn
to this point, and any facts to be elicited that will either confirm
or disprove my positions. From inquiries made of persons who
have had ample opportunity to observe what waters were either
permanently black or without tinge of such vegetable stain, I have
heard the following general statement of facts, on which my com-
ments will be offered as the facts are presented.

Streams and ponds of black waters are rarely seen above the falls
of the rivers ; and are believed to be very rarely found even twenty
to thirty miles above. They are never seen in the still higher
lime-stone region. If this opinion be correct, then these waters
are confined exclusively (as they certainly are mainly) to the region
of soil of the most acid quality. At the distance above the falls
where black waters are never found, the high land was naturally m
general of good quality, and the bottom or alluvial lands, on small
Btreams; invariably of good soil. Of course these qualities indi-

370 CONFINED TO ACID SOILS.

cate more of lime in tlie soil; and^ according to my views, also the
inability of water to become black, or at least to remain coloured.*

The waters of Blackwater river aad its tributary streams and
swamps become darker in autumn, owing to the low level of the
surface at that season. This is according to sound reason ; as eva-
poration of the solvent fluid necessarily increases the strength of
the solution. But this cause is held by most persons as secondary
in force to another, viz. : the dropping of the leaves, and especially
of the numerous black-gum trees, and their berries, at that season,
on the swamps and in the streams. Of course such ^is the source
of the colouring matter ; but it would produce no notable or abid-
ing effect, but for the want of lime both in the soil and in the wa-
ter. The extensive tide swamps on the creeks of James river, are
covered with a dense growth of trees, of which a large proportion
are black-gums. Yet in the numerous rills trickling or oozing out
of these soils, after some days of low tides, I have never observed
the water to be dark, or in the least discoloured. Yet the soil of
these tide swamps is as much of vegetable formation as any capa-
ble of bearing trees, and is believed to be more so than the swamp
lands of Blackwater river and its tributaries. Therefore it is not
the abundance of dead vegetable matter in a soil, nor the quantity or
kind of leaves furnished by the trees growing on it, which alone or
together produce coloured waters. The earthy portion of the soil
of these tide marshes and swamps, small as is its amount, is not
acid, but neutral, and the lime contained serves to prevent the wa-
ter remaining discoloured.

Yet this is not always the case on tide swamps. The waters of
Pocomoke river, flowing into the Chesapeake, are black, which I
presume is owing to the deficiency of lime in the water and in the
surface soil of the lands from which the waters flow.

The great Dismal Swamp of Virginia and its lake, and the still
more extensive swamps and lakes of North Carolina, all present
black waters, and which may all be accounted for by the reasons
here given.

Neither is it necessary that marl beds should be wanting to pro-
duce the effect of black waters. It is only necessary that the marl
(no matter how abundant) should be so far below the surface as
not to affect the overflowing waters, and that the soil of the higher
lands should be generally of acid quality. Such are the lands on
Blackwater river and its tributaries. And though marl was scarcely

* The extract translated from M. Puvis' ^^ Essai mr la Marne" and intro-
duced at page 150 of this essay, affords testimony that the facts in regard
to the existence and localities of black waters in France accord strictly
with the views presented in this article. This writer says that, "during the
month of August, the water of the ponds on calcareous soil does not hQ-
come blackish, as often happens in silicious ponds."

MARL AND MARLING IN EUROPE. 371

known anywhere there twenty years ago, it is now known to be
abundant, and generally to be found, though almost always a few
feet below the su]!;;face of the low lands.

Many persons who would concur with me as to the premises and
results, would yet ascribe the colouring of certain waters to the
more level surface of the land, and the more sluggish and stagnant
state of the waters ; and would suppose the absence of colouring
matter in the waters of. the upper country to be caused by the
rapidity of the descent and of the passage of the streams. This
would be a correct view, if the matter in question were the degree
of intensity of colour, instead of the existence or entire absence of
colour. It is true, and obvious, that if the coloured waters which
now creep and stagnate over the level lands below the falls, had as
rapid a descent and free discharge as the mountain torrents, their
colour could not become darker, with time, by long infusion of the
leaves, nor by evaporation of still waters. But though the colour
would be much more pale, its existence would not be the less cer-
tain. The source of colouring matter, the soaking of dead leaves,
&c., in rain-water, is as abundant in the upper as in the lower
country ; and the more rapid discharge of the waters, if no other
cause of clearing them operated, would not prevent their becoming
and remaining coloured, as generally, and, however more pale in
tint, would be seen as obviously, as in the most level lands. But
this is not all. Though there is almost no level land, and therefore
no swamps in the hilly or still less in the mountain region, there
are mill-ponds in the lower hilly country, and natural lakes in the
mountain region. If there was the slightest tint of dissolved colour-
ing matter in the streams, the waters when collected in these deep
reservoirs could not fail to exhibit the colour much more deeply.
Yet no one such fact is known, or is believed to have existence.

NOTE II. — Extension of the subject of pages 108 — 113.

The statements of British authors on marlj and their applications
of the name, generally incorrect^ and often contradictory. Both
the te7-ms '' marl" and " marling" have different significations
in Britain and in Virginia.

Custom has compelled me to apply improperly the name marl
to our deposits of fossil shells. But as I have defined the ma-
nuring by means of this substance, which is called marling (and
for which I suggested calxing as a much better and also more com-
prehensive name), to be simply rendering a soil calcareous — any
term used for that operation would serve, if its meaning was always
kept in view. But, unfortunately, this term (marling) is of old

372 MARL A>JD MARLING IN EUROPE.

and frequent use in English books^ with very different meanings.
The existence of these differences, and errors, has been stated
generally in a foregoing part of this Essay, and here will be adduced
the proofs, in quotations from many authors. I maintain, and will
establish the following propositions : —

1. By nearly or quite all of the older (and even some of the
modern) British authors, the term marl was applied to clays (or
earths) containing no calcareous matter ; dnd even when calcareous
earth was known to be contained in marl, that ingredient was not
deemed (if indeed it was) the essential or the most valuable fertiliz-
ing quality of the manure.

2. The marls of Europe, whether as correctly defined or under-
stood by modern writers and scientific agriculturists, or as often
miscalled and misunderstood by illiterate culti-vators — are very dif-
ferent from the deposits of fossil shells, called marl in this
couirtry.

3. Even when the chemical character, and the manuring action
(in like applications) of the marls of England and Virginia are
the same (that is, agreeing in being both calcareous) — still the ordi-
nary marlings of the former are quite a different manuring opera-
tion from the marling (or calxing) advised in this Essay — inasmuch
as the lands so manured in England were mostly calcareous before,
either by natural constitution, or by previous marling — and there-
fore were not made calcareous (or calxed) by the dressing in
question.

4. In many cases of published statements of, or references to
marling labours or improvements in England, the reader is left in
doubt whether the marl or the soil was calcareous — or which the
most so — and therefore, whether the " marling^' served to increase
or to lessen, or had not materially altered the proportion of the
previous calcareous contents of the soil.

5. The marling of England, especially, has been almost entirely
empirical — and not directed by theory, reasoning, or by inferences
drawn from the known (or even surmised) chemical constitutioa
of either the soil or the earthy manure applied..

These assertions refer principally, but not exclusively, to the
•writers on agriculture of former and less enlightened times than
the present or recent. Scarcely any exception is known in works
much older than the institution of the British Board of Agricul-
ture, in 1795. Before that time, the errors which I shall adduce
prevailed almost universally, in books as well as in vulgar language
and opinion. And these older writers were, to much later times,
the unquestioned authorities of the earliest agricultural writers of
America, as well as of all our othter readers and thinkers. And
the aid of all the more correct information as to the true character
of marl, afforded by the more recent British writers, it seems has

C9RRECT DEFINITIONS OF MARL. 373

cleared away but little of the before general obscuration on this
sabject in their own country. Of such remaining ignorance, or its
appearance, striking and recent examples will be presented.

The passages to be quoted will exhibit so fully the contradictions
and ignorance generally prevailing as to the nature of whatever
was called marl, and the operation of calcareous manures generally,
that it will not be required for me to express dissent in every case,
or to point out the errors of facts or of reasoning, which will appear
so manifestly and abundantly in some of the quotations.

But besides the errors and even absurdities of opinions and prac-
tices in regard to marl or lime, which some of these passages will
show, there will be presented in connexion some correct, precise,
and very interesting facts. Among these will be definitions and
descriptions by recent authors of marl proper, and also the varieties
known in Britain by the provincial names of '^ clay" or "clay
marl," and the "shell marl" formed only in ancient lakes, since
changed to peat bogs. These passages, though some of them are
the very latest in the order of time, will be offered first — so that
what is sound and true may be kept in view, through all the mass
of error that will be afterwards presented.

1. ''Compact limestone, by an increase of argillaceous matter, passes
into marl." "Marl is essentially composed of carbonate of lime and clay,
in various proportions." — Cleaveland's Mineralogy.

2. " Marl is a compound of carbonate of lime, argil [finest clay] and of
eilicious sand. The sand appears to be only in a state of mixture, and
may be, when not very fine, separated easily. But the argil and carbo-
nate of lime in marl (like the alumina and silica in argil), seem to be a
[chemical] combination, and not a simple mixture." — Puvis — Essai sur la
Marne.

"Marl seems to be, in most cases, a formation of fresh water." — Puvis —
Translation, Farmers' Register, vol. iii. p. 692.

3. " Marl is a combination of carbonate of lime and clay. These two
bodies are usually found in so complete a state of amalgamation, that it is
impossible to distinguish the particles of one from those of the other, either
with the naked eye, or with the aid of the microscope." " When water is
poured upon marl, that fluid penetrates, with greater or less facility, into
all its pores, destroys the cohesion of the parts, separates them from one
-another, and reduces them to a fine powder. This is one of the essential
properties, which serves as the first distinction of marl," &c.

"It certainly cannot be admitted as a principle that any kind of earth -
which loses its aggregation in water must necessarily be marl, since some
very poor clays are affected in the same manner ; but if any kind of earth
is not spontaneously reduced to powder by the action of water, we may
feel convinced that it is not marl. Every kind of marl, even that which is
called 'stony,' becomes soft and pulverized in water." — 'Von, Thaer's Prin^
crples of Agriculture.

It appears from different authors that the proportions of carbo-
nate of lime in marl usually vary from 20 to more than 60 pep

374 CLAY MARL AND SHELL MARL.

cent. When mucli richer, say near or quite 80 per cent., it becomes
of stony hardness, or passes into lime-stone.

In Britain the marls most abounding in clay are called ''clay
marl," and vulgarly " clay'' simply. This is the kind most gene-
rally used, and in enormous quantities. Stephens (in the latest
edition of his ''Book of the Farm"), oflFers the first precise in-
formation that I have seen, as it is also the most recent of the
component parts of this marl, as follows : — from Johnston on the
Use of Lime.

4. " The following analysis may give a fair idea of the composition of a
clay marl." This specimen was found in Ayrshire.

Carbonate of lime . . . . 8.4

Oxide of iron and alumina

Organic matter

Clay, and silicious matter

Water

2.2

2.8

84.9

1.4

99.7

Every one who has observed what is called marl in lower Vir-
ginia will recognise its entire disagreement with the true marl
described in all the foregoing quotations, in every physical or
mechanical property, in texture, and in its manifest origin or for-
mation.

5. *' Shell 3Iarl. — In some parts of the country, as in Forfarshire [Scot-
land,] this substance is found in great quantities associated with peat.
. . . . It is taken out of the bogs by means of a boat mounted with a
dredging appoiratus. When of fine quality and in a dry state, it is as
"White as lime, not crumbling down into powder like quick-lime, but cutting

something like cheese, with the spade It is applied at 40 to

50 bolls (8 cubic feet) to the acre. When applied as lime, it is beneficial;
but, as is often the case, when applied solely as manure, in quantities of 35
to 45 cubic yards to the acre, it never fails to be mischievous. It does not
easily injure new fresh land ; [Qu. the first time applied ?] but when re-
peated frequently, as a sole manuring, I have seen land reduced to such a
state of pulverization, that the foot, with a stamp, sank into the ground as
deep as the ankle. Applied to lands followed by severe cropping, it has
reduced them to a state of utter sterility, which they have not recovered
from to this day." — [Stephens' Book of the Farm, or Farmers' Guide, 1850 ;
Headrick's Survey of Forfarshire.)

This "shell marl" consists of
"Carbonate of lime
Oxide of iron and alumina .
Organic matter ....
Insoluble, chiefly silicious matters

100. 100.

This substance, according to its analysis above, is undoubtedly
the most valuable of all calcareous manures. But still it is nob

Top of bed.

Bottom of bed

77.G

81.7

1.8

0.6

14.6

14.6

6.0

3.1

"marls'^ not calcareous. 375

marl, either as understood by mineralogists and scientific agricul-
turists in Europe, or as marl is known in this country. This peculiar
formation (the deposit of the shells of fresh-water molluscs in what
had been ancient lakes, and which since became peat-bogs), has
been referred to previously, and will be again, in another connexion.
So far, all the earths called marl have been calcareous. But all
are not so that are recognised under that name, even by modern
and well informed writers, who certainly knew the chemical cha-
racter (in this respect), of the earths referred to. In " British
Husbandry,'' a recent work of authority, prepared for and pub-
lished by the " Society for the Diffusion of Knowledge," in treating
of marl, the following passages occur : —

6. "A bluish "marl much used in some parts of Ireland, and long cele-
brated as a manure, makes no ebullition with acids ; neither do several of
the red marls ; yet many of them are known to be productive of great im-
provement to land." p. 265. "Out of 12 specimens of marl submitted to
Sir Humphrey Davy, 11 were found to contain calcareous earth; but the
result of many other trials of marls, from different parts of the country,
and found by farmers to produce an ameliorating effect on the land, yet
proves them to be, in many instances, wholly deficient in that substance."
See "Marl" in Holland's Report on Cheshire.

Now whatever of fertilizing properties these earths contained,
they were not marl in the proper understanding of that term, nor
do they agree with our marl in any stated character, either chemi-
cal or physical.

An earlier, though yet a modern writer, Marshall, has also de-
scribed a valuable " marF' of Norfolk, England, which is almost
destitute of calcareous matter.

7. " The red earth which has been set upon the lands of this district, in
great abundance, as 'marl,' is much of it in a manner destitute of calca-
reous matter ; and, of course, cannot, with propriety, be classed among
marls. Nevertheless, a red fossil is found, in some parts of the district,
which contains a proportion of calcareous matter. The marl of Croxall
(in part of a stone-like, or slaty contexture, and of a light red colour) is
the richest in calcareosity ; one hundred grains of it afford thirti/ grains of
calcareous matter ; and seventy grains of fine, impalpable, red-bark-like
powder,* And a marl of Elford (in colour and contexture various, but re-
sembling those of the Croxall marl) affords near twenty grains. Yet the

* This marl is singularly tenacious of its calcareous matter ; dissolving
remarkably slowly. One hundred grains, roughly pounded, was twenty-
four hours in dissolving ; and another hundred, though pulverized to mere
dust, continued to effervesce twelve hours ; notwithstanding it was first
saturated with "water, and afterward shaken repeatedly. The Breedon stone,
roughly pounded, dissolved in half the time ; notwithstanding its extreme
hardness. [I strongly suspect that Marshall used nitric acid in this trial,
and was deceived by the slow solution of carbonate of iron, with some
ebullition, and that there was as little calcareous earth as in the other
case,s. I have never experienced such slow solution of carbonate of lime,
ip strong acid. E. R.j

376 "marls'

marl of Barton, ^n the opposite side of the Trent — though somewhat of a
similar coiitextuio, but of a darker, more dusky colour — is in a manner
destitute of calcareosity ! one hundred grains of it yielding little more than
one grain — not two gi-ains of calcareous matter. Nevertheless, the pit, from
■which I took the specimens analyzed, is an immense excavation, out of
•which many thousand loads have been taken. And the marls of this
neighbourhood (which mostly differ in appearance from those described,
having generally that of a blood-red clay, interlayered, and sometimes in-
termingled with a white gritty substance) are equally poor in calcareosity.
One hundred grains of the marl of Statford (which I believe may be taken
as a fair specimen of the red clays of this quarter of the district) afford
little more than two grains of calcareous matter — lodged not in the sub-
stance of the clay, but in its natural cracks, or fissures. Yet this is said
to be 'famous marl;' and from the pits which now appear, has been laid
on in great abundance.

"I do not mean to intimate, that these clays are altogether destitute of
fertilizing properties, on their first application. It is not likely that the
large pits which abound in almost every part of the district, and which
must have been formed at a very great expense, should have been dug,
without their contents being productive of some evidently, or at least ap-
parently good effect, on the lands on which they have been spread. I con-
fess, however, that this is but conjecture ; and it may be, that the good
effect of the marls first described being experienced, the fashion was set ;
and the distinguishing quality being unknown, or not attended to, marls
and clays were indiscriminately used." — -Marshall's Midland Counties, vol.
i. p. 152,

8. "On the southern banks of the Anker, is found a gray marl; re-
eembling in general appearance the marl of Norfolk, or rather the fuller's
earth of Surrey. In contexture it is loose and friable. This earth is sin-
gularly prodigal of its calcareosity. The acid being dropped on its surface,
it flies into bubbles as the Norfolk marl. This circumstance, added to that
of a striking improvement, which I was shown as being effected by this
earth, led me to imagine that it was of quality similar to the marls of
Norfolk. But, from the results of two experiments — one of them made
with granules formed by the weather, and collected on the site of improve-
ment, the other with a specimen taken from the pit, it appears that one
hundred grains of this earth contain no more than six grains of calcareous
matter ! the residuum a cream-coloured saponaceous clay, with a small
proportion of coarse sand." — 3IarshaU's 3[idland Counties, vol. i. p. 155.

In the latter quotations are presented separately the proofs from
authors fully competent to try and know the remarkable facts
stated of many well approved ''marls," so called, being nearly or
entirely destitute of calcareous earth ! I will now go bt. "S
to older writers, who treat of marls without noticing that ingredient
as being present, or without seeming to be aware that its presence
would be useful.

The learned and also practical Miller thus defin-es and describes
marl, in the Abridgment of the Gardener's Dictionary^ fifth Lon-
don edition, 1763, at the article iftiarl :

*' Marl is a kind of clay which is become fatter and of a more enriching
quality, by a better fermentation, and by its having lain so deep in the
earth as not to have spent or weakened its fertilizing quality by any pro-
duct.

MARL NOT KNOWN TO BE CALCAREOUS. 377

"Marls are~of different qualities in diflferent counties of England. There
are reckoned four kinds of marl in Sussex, a- gray, a blue, a yellow, and a
red ; of these the blue is accounted the best, the yellow the next, and the
gray the next to that ; and as for the red, that is the least valuable.

" In Cheshire they reckon six sorts of marl :

*' 1. The cowshut marl, which is of a brownish colour, with blue veins in
it, and little lumps of chalk or limestone ; it is commonly found under clay,
or low black land, seven or eight feet deep, and is very hard to dig.

<' 2. Stone, slate, or flag marl, which is a kind of soft stone, or rather
slate, of a blue or bluish colour, that will easily dissolve with frost or rain.
This is found near rivers, and the sides of hills, and is a very lasting sort
of marl.

"3. Peat marl, or delving marl, which is close, sti'ong,* and very fat,
of a brown colour, and is found on the sides of hills, and in wet or
boggy grounds, which have a light sand in them about two feet or a yard
deep.

" 4. Clay marl ; this resembles clay, and is pretty near akin to it, but is
fatter, and sometimes mixed with chalk stones.

*' 5. Steel marl, which lies commonly in the bottom of pits that are dug,
and is of itself apt to break into cubical bits ; this is sometimes under
sandy land.

<< 6. Paper marl, which resembles leaves or pieces of brown paper, but
something of a lighter colour; this lies near coals.

*' The properties of any sorts of marls, by which the goodness of them
may be best known, are better judged of by their purity and uncompound-
edness, than their colour : as if it will break in pieces like dice, or into thin
flakes, or is smooth like lead ore, and is without a mixture of gravel or sand ;
if it will slake like slate-stones and shatter after wet, or will tumble into
dust, when it has been exposed to the sun ; or will not hang and stick to-
gether when it is thoroughly dry, like tough clay ; but is fat and tender,
and will open the land it is laid on, and not bind ; it may be taken for
granted that it will be beneficial to it."

In all these descriptions, so minutely stated, both general and
particular, and of ten diiFerent varieties of marl, there is no indica-
tion that calcareous earth is an essential constituent part; nor in-
deed does it appear that it was deemed a constituent part, proper,
even in the two varieties, in which bits of chalk are found. For
these are accidental admixtures, as would be any silicious sand, or
gravel, or land, or even river shells ; none of which, if found there-
in, would properly belong to true marl.

The well-deserved reputation of Miller is a sufficient guaranty
that there was no more full or correct knowledge of marl, in his
time, than he possessed, and taught in the foregoing extracts.

9. Johnson^ s Dictio7iary (octavo edition) defines marl in pre-
cisely the words of the first sentence of Miller, as quoted above.

10. Walker's Dictionary (octavo edition) gives only the fol-
lowing definition — " Marl — a kind of clay much used for ma-
nure.''

* ** Strong" applied to soil in England means stiff or clayey — and in this
sense I presume the word is used above. E. II.
32*

878 MARL NOT KNOWN TO BE CALCAREOUS.

11. Kir wan, on tlie authority of Arthur Young and the Bath
Memoirs [1783,] states that,

"In some parts of England, where husbandry is successfully practised,
any loose clay is called marl ; in others, marl is called chalk, and in others,
clay is called loam.^^ — Kirwan on Manures, p. 4.

12. A Practical Treatise on Husbandry (second London edition,
4to. 1762,) which professes to be principally compiled from the
writings of Duhamel, Evelyn, Home, and Miller, supplies the fol-
lowing quotations :

"But of all the manures for sandy soils, none is so good as marl. There
are many different kinds and colours of it, severally distinguished by many
writers ; but their virtue is the same ; they may be all used upon the same
ground, without the smallest difference in their effect. The colour is either
red, brown, yellow, gray, or mixed. It is to be known by its pure and un-
compounded nature. There are many marks to distinguish it by ; such as
its breaking into little square bits; its falling easily into pieces, by the
force of a blow, or upon being exposed to the sun and the frost ; its feeling
fat and oily, and shining when it is dry. But the most unerring way to
judge of marl, and know it from any other substance, is to break a piece as
big as a nutmeg, and when it is quite dry, drop it into a glass of clear
water, where, if it be right, it will dissolve and crumble, as it were, to
dust, in a little time, shooting up sparkles to the surface of the water." —
p. 27.

Not the slightest hint is here of any calcareous ingredient being
necessary, or even serving in any manner to distinguish marl. But
afterwards, in another part of this work, when shell marl is slightly
noticed, it is said :

"This effervesces strongly with all acids, which is perhaps chiefly owing
to the shells. There are very good marls which show nothing of this effervescence ;
and therefore the author of the New System of Agriculture judged right in
making its solution in water the distinguishing mark." — p. 29.

The last sentence declares, as clearly as any words could do, that,
in the opinion of the author, no calcareous ingredient is necessary,
either to constitute the character, or the value of marl. And
though it may be gathered from other parts of this work, that what
is called marl generally contains calcareous earth, yet no import-
ance seems attached to that quality, any more than to the particular
colour of the earth, or any other accidental or immaterial appearance
of some of the varieties described.

The '^ shell marl" alluded to above, without explanation might
be supposed to be similar to our beds of fossil shells, which are
called marl. The two manures are very different in form, appear-
ance, and value, though agreeing in both being calcareous. The
manure called shell marl by the work last quoted from, is described
there with sufficient precision, and more fully in several parts of the
Edinburgh Farmers' Magazine,* and in the Memoirs of the Phila-

* See Farmers' Kegister, vol. i., p. 90.

CALCAREOrS QUALITY NOT KNOWN. 6t\)

delpbia Agricultural Society,* [and in the late edition of Stephens'
Book of the Farm, as quoted above]. It is. still more unlike mcwlf
properly so called, than any of the substances described under that
name, in the foregoing quotations. This manure is-almost a pure
calcareous earth, being formed of the remains of small fresh-water
shells deposited on what were once the bottoms of lakes, but which
have since become covered with hog or peat soil. If I may judge
from our beds of mussel shells (to which this manure seems to bear
most resemblance), much putrescent animal matter is combined
with, and serves to give additional value to these bodies of shells.
This kind of manure is sold in Scotland by the bushel, at such
prices as show that it is very highly prized. It seems to be found
but in few situations, and though called a kind of marl, is never
meant when that term alone is used by British writers.

13. A much older work than either of these referred to fur-
nishes in part the definitions and even the words used above. This
is the " Systema Agricultures, the Mystery of Husbandry dis-
covered,'' published in 1687 ', and the author or compiler of that
old work was probably indebted to others still older for his descrip-
tion of marl. For new books on agriculture, more especially,
have been most generally made by compiling and copying from
older ones.

*' Marie is a very excellent thing, commended of all that either write or
practise any thing in husbandry. There are several kinds of it, some stojiy,
some soft, white, gray, russet, yclloio, blew, black, and some red : It is of a
cold nature and saddens land exceedingly ; and very heavy it is, and -will
go downward, though not so much as lime doth. The goodness or badness
thereof is not known so much by the colour, as by the purity and uncom-
poundness of it ; for if it will break into bits like a dye, or smooth like lead
oar, without any composition of sand or gravel ; or if it will slake like slate-
Btones, and slake or shatter after a shower of rain, or being exposed to the
eun or air, and shortly after turn to dust when it's thoroughly dry again,
and not congeal like tough clay, question not the fruitfulness of it, notwith-
standing the difference of colours, which are no certain signs of the good-
ness of the marie. As for the slipperiness, viscousness, fattiness, or oyliness
thereof, although it be commonly esteemed a sign of good marie, yet the
best authors affirm the contrary — viz. that there is very good viarle which
is not so, but lieth in the mine pure, dry and short, yet nevertheless if you
water it, you will find it slippery. But the best and truest rule to know
the richness and profit of your marie, is to try a load or two on your lands,
in several places and in different proportions.

" They usually lay the same on in small heaps, and disperse it over the
whole field, as they do their dung ; and this marie will keep the land
whereon it is laid, in some places ten or fifteen, and in some places thirty
years in heart: it is most profitable in dry, light, and barren lands, such as
is most kind and natural for rye, as is evident by Mr. Blithers experiment
in his chapter of marie. It also aflFordeth not its vertue or strength the first
year, so much as in the subsequent years. It yields a very great increase

* Vol. iii. p. 206.
32*

380 AMERICAN OPINIONS DERIVED FROM ENGLISH.

and advantage on high, sandy, gravelly, or mixed lands. Though never so
barren, strong clay ground is unsuitable to it; yet if it can be laid dry,
marie may be profitable on that also."

The author then proceeds to direct the mode of application more
particularly ; and if there were any doubt as to his total ignorance
(or otherwise denial) of calcareous earth being necessary to the
constitution of marl, that doubt would be removed by a subsequent
sentence.

"You shall observe (saith Markham,) that if you cannot get dry, per-
fect, and rich marie, if then you can get of that earth which is called
fuller's earth (and where the one is not, commonly the other is), then you
may use it in the same manner as you should do maiie, and it is found to
be very near as profitable."

14. Evelyn's Terra, or Philosophical Discourse of Earths,
&c., delivered before the Royal, Society in 1675, has the following
passage :

'' Of marie (of a cold sad nature, a substance between clay and chalk),
seldom have we such quantities in layers as we have of forementioned
earth ; but we commonly meet with it in places aifected to it, and it is
taken out of pits, at different deptlis, and of divers colours, red, white,
gray, blue, all of them unctuous, and of a slippery nature, and differing in
goodness ; for being pure and immixt, it sooner relents after a shower, and
when di-yed again, slackens, and crumbles into dust, without induration,
and growing hard again. They are profitable for barren grounds, as
abounding in nitre ; and sometimes there has been found in marie, delfs, a
vitriolic wood, which will kindle like coal."

The opinions expressed in the foregoing extracts, prove suffi-
ciently that it was not the ignorant cultivators only, who either did
not know of, or attached no importance to the calcareous ingredient
in marl; and it was impossible that, from any number of such
authors, an American reader could learn that either the object or
the effect of marling was to render a soil more calcareous — or that
our bodies of fossil shells resembled marl in character, or in opera-
tion as a manure. Of this, the following quotation from a modern
and also an American agriculturist and author, Bordley, will fur-
nish striking proof — and the more so as he refers frequently to the
works of iVnderson, and of Young, who treated of marl and of cal-
careous manures, in a more scientific and correct manner than had
then been usual. This author cannot be justly charged with in-
attention to the instruction to be gained from books; for bis greatest
fault, as an agriculturist, is his fondness for applying the practices
of the most improved husbandry of England, to our lauds and
situations, however diiferent and unsuitable — which he carried to
an extent that is ridiculous as theory, and would be ruinous to the
farmer who should so shape his general practice.

15. '*! farmed in a country [the Eastern Shore of Maryland] where
habits are against a due attention to manures : but having read of the ap-

CALCAREOUS PART NOT PRIZED.

#»i

plication of marl as a manure, I inquired where there was any in the penin-
sula of the Chesapeake in vain. My own farm had a grayish clay which to
the eye was marl : but because it did not effervesce with acids, it was
given up when it ought to have been tried on the land, especially as it ra-
pidly crumbled and fell to mud, in water, with some appearance of effer-
Tescence." — Bordleifs Husbandry, 2d ed., p. 55.

That peninsula, through which Mr. Bordley in vain inquired for
marl, has immense quantities of the fossil shells which we impro-
perly call by that name. But as his search was directed to marl
as described by English authors — and not to calcareous earth sim-
ply— it is not to be wondered at that he, well-read and intelligent
as he was, should neither find the former substance, nor attach
enough importance to the latter, to induce the slightest remark on
its probable use as manure.

16. The Practical Treatise on Husbandry , among the directions
for improving clay land, has what follows :

** Sea sand and sea shells are used to great advantage as a manure,
chiefly for cold strong [i, e. clay] land, and loam inclining to clay. They
separate the parts ; and the salts which are contained in them are a very
great improvement to the land. Coral, and such kind of stony plants
which grow on the rocks, are filled with salts, which are very beneficial to
land. But as these bodies are hard, the improvement is not the first or
(second year after they are laid on the ground, because they require time to
pulverize them, before their salts can mix with the earth to impregnate it.
The consequence of this is, that their manvire is lasting. Sand, and the
Bmaller kind of sea weeds, will enrich land for six or seven years ; and
shells, coral, and other hard bodies, will continue many years longer.

" In some countries fossil shells have been used with success as manure ;
but they are not near so full of salts, as those shells which are taken
from the sea-shore ; and therefore the latter are always to be preferred.
Sea sand is much used as manure in Cornwall. The best is that which is
intimately mixed with coral." — p. 21.

After stating the manner in which this " excellent manure'^ is
taken up from the bottom, in barges, its character is thus con-
tinued :

*< It [i. e. the sea sand mixed with coral, as it may happen] gives the
heat of lime, and the fatness of oil, to the land it is laid upon. Being
more solid than shells, it conveys a greater quantity of fermenting earth in
equal space. Besides, it does not dissolve in the ground so soon as shells,
but decaying more gradually, continues longer to impart its warmth to the
juices of the earth."

Here are described manures which are known to be calcareous,
which are strongly recommended — but solely for their supposed
mechanical effect in separating the parts of close clays, and on ac-
count of the salts derived from sea-water, which they contain.
Indeed, no allusion is made to any supposed value, or even to the
presence of calcareous earth, which forms so large a proportion of
these manures ; and the fossil shells (in which that ingredient is

382 ERRORS OE MODERN AUTHORS.

more abundant, more finely reduced, and consequently more fit for
both immediate and durable efifects) are considered as less effica-
cious than solid sea shells, and inferior to sea sand. All these
substances, besides whatever service their salts may render, are pre-
cisely the same kind of calcareous manure, as our beds of fossil
shells furnish in a difierent form. Yet neither here nor elsewhere,
does the author intimate that these manures and marl have similar
powers for improving soils.

The foregoing quotations show what opinions have been expressed
by English writers of reputation, and what opinion would thence
necessarily be formed by a general reader of these and other agri-
cultural works, of the nature of what is called marl in England, as
well as what is so named in this part of our country. I do not
mean that other authors have not thought more correctly, and
sometimes expressed themselves with precision on this subject.
Mineralogists define marl to be a calcareous clay ; and in this cor-
rect sense, the term is used by Davy, and other chemical agricul-
turists. Such authors as Young and Sinclair also could not have
been ignorant of the true composition of marl ; yet even they have
used so little precision or clearness, when spoaking of the efi"ects of
marling, that their statements (however correct they may be in the
sense they intended them) convey no exact information, and have
not served to remove the erroneous impressions made by the great
body of their predecessors. Knowing as Young did [see above,
11] the confusion in which this subject was involved, it was the
more incumbent on him to be guarded in his use of terms so gene-
rally misapplied. Yet considering his practical and scientific
knowledge as an agriculturist, his extensive personal observations,
and the quantity of matter he has published on soils and calcareous
manures, his omissions are more remarkable than those of any
other writer. In such of his works as I have met with, though
full of strong recommendations of marling, in no case does he state
the composition of the soil (as respects its calcareous ingredient),
or the proportion added by the operation ; and generally notices
neither, as if he viewed marling just in the same loose and incor-
rect manner as most others have done. These charges are supported
by the following extracts and references.

17. Young's Farmer's Calendar, 10th London edition, page
40. — On marling. Through nearly four pages this practice is
strongly recommended — but the manures spoken of, are regularly
called '^ marl or clay,'' and their application, " marling or claying."
Mr. Rodwell's account of his practice (which I before referred to,
p. Ill,) is inserted at length. On leased land he " clayed or marled"
eight hundred and twenty acres with one hundred and forty thou-
sand loads, and at a cost of four thousand nine hundred and fifty-
eight pounds — and the business is stated to have been attended

ERRORS OP ARTHUR YOUNG. 883

with great profit. At last, tlie author lets us know that it is not
the same substance that he has been calling " marl or clay" — and
that fhe marl effervesces strongly with acids, and the clay slightly.
But we are told nothing more precise as to the amount of calcare-
ous ingredients, either in the manures, or the soil ; and even if we
were informed on those heads (without which we can know little or
nothing of what the operation really is), we are left ignorant of
how much was clayed, and how much marled. It is to be inferred,
however, that the clay was thought most serviceable, as Mr. Rod-
well says —

*'Clay is much to be preferred to marl on those sandy soils, some of
which are loose, poor, and even a black sand."

18. Young's Survey of Norfolk (a large and closely printed oc-
tavo volume) has fourteen pages filled with a minute description of
the soils of that county ; but without any indication whatever of
the proportion, presence, or absence, of calcareous earth in that
extensive district of sandy soils, so celebrated for their improve-
ment by marling — nor in any other part of the county. The wastes
are very extensive : one of them (page 385) eighteen miles across,
quite a desert of sand, " yet highly improvable.'' Why it is im-
provable he does not say, as of this also, no information is given
as to its calcareous constitution.

19. The section on marl (page 402, of the same work) gives
concise statements of its application, with general notices of its
eff'ects, on near fifty difi"erent parishes, neighbourhoods, or separate
farms. Among all these, the only statements from which the cal-
careous nature of the manure may be gathered, are (page 406), of
a marl that " ferments strongly with acids'' — another (page 409),
that marling at a particular place destroys sorrel — and (page 410)
that the marl is generally calcareous, and that that containing the
onost clay, and the least calcareous earth j is preferred by most per-
sons, but not by all.

20. Young's General View of the Agriculture of Suffolk (an
octavo of 432 pages of close print), in the description of soils,
affords no information as to any of them being calcareous, or other-
wise; yet the author mentions (page 3) having analyzed some of
the soils, and reports their aluminous and silicious ingredients.
Nor can more be learned in this respect, in the long account after-
wards given of the " marl" which has been very extensively applied
also in the county of Suffolk. We may gather, however, from the
following extracts, that the '' marl or clay" of Suffolk is generally
calcareous, but that this quality is not considered the principal
cause of its value ; and further, that crag, a much richer calcareous
manure (which seems to be the same with our richest beds of fossil

384 ERRORS OP ARTHUR YOUNG.

shells, or marl), is held to be injurious to the sandy soils, which
are so generally improved by what is there called marl.

"Claying — a term in SuflFolk, which includes marling; and indeed the
earth carried under this term is very generally a clay marl ; though a pure,
or nearly a pure clay, is preferred for very loose sands.^' — Young's Suffolk,
p. 186.

After speaking of the great value of this manure on light lands,
he adds :

"But when the clay is not of a good sort, that is, when there is really
none, or scarcely any clay in it, but is an imperfect and even a hard chalk,
there are great doubts how far it answers and in some cases has been spread
to little profit."— p. 187.

"Part of the under stratum of the county is a singular body of
cockle and other shells, found in great masses in various parts of the
country, from Dunwich quite to the river Orwell, &c." — " I have seen pits
of it to the depth of fifteen or twenty feet, from which great quantities had
been taken for the purpose of improving the heaths. It is both red and
white, and the shells so broken as to resemble sand. On lands long in
tillage, the use is discontinw.d, as it is found to make the sands blow more."
[That is, to be moved by the winds.] — p. 6.

21. The Essay on Manures, by Arthur Young, for which the
author was honoured with the Bedford medal, speaks distinctly
enough of the value of marl being due to its calcareous ingredient
(as this author doubtless always knew, notwithstanding the loose-
ness of most of his remarks on this head) ; but at the same time
he furnishes some of the strongest examples of absurd inferences,
or of gross ignorance of the mode in which calcareous earth acts
as an ingredient of soil, and the proportion which soils ought to
contain. These are his statements, and his reasoning thereon :

"It is extremely difficult to discover, from the knowledge at present
possessed by the public, what ought to be the quantity of calcareous earth
in a soil. The best specimen analyzed by Giobert had 6 per cent. ; by
Bergman, 30 per cent. ; by Dr. Fordyce, 2 per cent. ; a rich soil, quoted
by Mr. Davy, in his lecture at the Royal Institution, 11 per cent. This is
an inquiry, concerning which I have made many experiments, and on soils
of the most extraordinary fertility. In one, the proportion was equal to
9 per cent. ; in another 20 per cent. ; another, 3 per cent. ; and in a spe-
cimen of famous land, which I procured from Flanders, 17 per cent. But
the circumstance which much perplexes the inquiry is, that many poor
soils possess the same or nearly the same proportions as these most
fertile ones. To attain the truth, in so important a point, induced me to
repeat many trials, and to compare every circumstance ; and I am disposed
to conclude, that the necessity of there being a large proportion of calcareous
earth in a soil depends on the deficiency of organic [i. e. vegetable or animal]
matter ; of that organic matter which is [partly] convertible into hydrogen
gas. If the farmer finds, by experiment, that his soil has but a small
quantity of organic matter, or knows by his practice that it is poor, and
not worth more than lOs., 15s. or 20«. an acre, he may then conclude that there
ought to be 20 per cent, of calcareous earth in it ; but, if, on the contrary, it
abound with organic matter, and be worth in practice a much larger rent,

ERRORS OF ARTHUR YOUNG. 385

in that case his marl cart will not be called for, though there be but 5 per
cent, or even less, of calcareous matter." — Younfs Essay on Manures— ^
Sect. 2.

It is scarcely necessary to state, that the opinion of calcareoua
matter being needed in larger quantities in proportion to the defi-
ciency of the ^^ organic" or putrescent matter, is directly opposed
to the reasoning of this essay. If a poor soil were made to contain
twenty per cent, of calcareous matter, by applying lime, chalk, or
marl, the quantity and the expense would be so enormous as not to be
justified by any possible return ; and besides, it would lessen rather
than increase the product of a poor soil. The fact named as strange
by Young, that some rich soils contain very small, and others very
large proportions of calcareous earth, is easily explained. If a na-
tural soil contains any excess of calcareous earth, even though but
one per cent., it shows that there is so much to spare, after its
having served every purpose of neutralizing acids and combining
with putrescent matter. If there were twenty per cent, more of
calcareous matter, it would be useless, and indeed probably hurtful,
until met by an additional supply of putrescent matter. Young's
statement that some poor soils agree precisely with other rich soils,
in their contents of calcareous earth, does not necessarily contra-
dict my doctrine that a proper proportion of calcareous earth will
enable any soil to become rich, either in a state of nature, or un-
der mild cultivation, and for the following reasons :

22. 1st. The correctness of Young's analyses of soils may be
well doubted; and if he used the then usual process. for separating
calcareous earth, he was obliged to be incorrect on account of its
unavoidable imperfection, as has been already explained at page
57. 2d. It cannot be known positively what was the original state
of fertility of most cultivated soils in England, nor whether they
were suljjected to exhausting or improving cultivation, for centuries
before our information from history begins. 3d. Lime has been
there used for a long time, and to great extent ; and chalk and
marl were applied as manures before the time of the Roman con-
quest, as stated by Pliny (or more than 1800 years ago); so that it
cannot be always known whether a soil has received its calcareous
ingredient from nature, or the industry of man. 4th. It is known
that severe cropping after liming, and also excessive doses of cal-
careous earth, have rendered land almost barren; of which the
following extracts offer sufficient proof: —

"Before 1778 [in East Lothian], the out-field ^\d not receive any dung
except what was left by the animals grazed upon it. In many cases, out-
field land was limed ; and often with singular advantage. The after man-
agement was uniformly bad ; it being customary to crop the limed out-field
with barley and oats successively, so long as the crop was worth cutting.
In this way numerous fields suffered so severely as to be rendered almost
sterile for half a century afterwards." — Farmer's Magazine^ p. 53, vol. xii.

33

386 LORD KAMES AND SIR JOHN SINCLAIR.

"An overdose of shell marl [that from under peat, albove described],
laid perhaps an inch thick, produces for a time large crops. But at last it
renders the soil a caput mortuum, capable of bearing neither corn nor
grass; of which, there are too many examples in Scotland, &c. — Gentle-
man Farmer, p. 378.

23. Yet the last-quoted writer (Lord Karnes) elsewhere states
(at page 379), that as much clay marl as contains 1500 bolls (or
9000 bushels), of pure calcareous earth to the acre, is not an over-
dose in Scotland.

The next following evidences have been referred to, and some
of them at greater length, in previous parts of this essay. They
will be again adduced here, because of their peculiar importance in
sustaining my positions. The particular opinions here to be quoted
are from writers of high character and authority, as scientific agri-
culturists, or chemists. The names of Sinclair, Davy, and Morton
(and also Young, before quoted), deservedly stand among the
highest. Moreover, they are all modern authorities. They seve-
rally had all the lights on calcareous manures which existed before
the last thirty years (or later) ; and certainly each of them well knew
what was true marl, its mineralogical and chemical character, and
also what was calcareous soil. Sir John Sinclair will be the first
of these quoted.

24. ^^ Marl. Of this substance, there are four sorts, rock — slate — clay —
Jind shell marl. The three former are of so heavy a nature that they are
seldoi# conveyed to any distance ; though useful when found below a lighter
soil, to which they can be applied without incurring much expense. But
shell marl is specifically lighter, and consists entirely of calcareous matter
(the broken and partially decayed shells of fish), which may be applied a»
a top-dressing to wheat and grass, when it would be less advantageous to
use quick-lime." [This is the kind of manure referred to in extract 12, and
there more particularly described.] "In Lancashire and Cheshire, clay,
or red marl, is the great source of fertilization, &c." — "The quantity
used is enormous ; in many cases about three hundred middling cart loads
per acre, and the fields are sometimes so thickly covered as to have the
appearance of a red soiled fallow, fresh ploughed". — Sinclair's Code of Ag-
riculture, Amer. ed. (Hartford) p. 138, and 5tli London ed.

This account of the Lancashire improvements made by red clay
marl closes with the statement that " the effects are represented to
be beneficial in the highest degree," which is fully as exact an ac-
count of profit, or increased production, as we can obtain of any
other marling. Throughout, there is no hint as to the calcareous
constituents of the soil or the manure, or whether either rock, clay,
or slate marls, generally, are valuable for that or for other reasons;
nor indeed could we guess that they contained any calcareous earth,
but for their being classed with many other substances, under the
general head of calcareous manures.

But we may leani from other sources that the " red marl" of
Lancashire is calcareous, and that the soil to which it was applied
is also calcareous. This character of the marl is distinctly stated

MARLING NOT TO MAKE SOIL CALCAREOUS. 387

by the Agricultural Surveyor of Lancashire, in his Report to the
Board of Agriculture (of which Sir John Sinclair was president),
and the calcareous character of the soil is inferred from its being
of the "new red sand-stone formation/' which is highly calcareous,
and also from Morton's speaking of the " red marl" in some parts
forming the surface soil.

25. The Report of the Agricultural Survey of Lancashire (made
to and published by the Board of Agriculture) states the general
practice, and also particular cases of the enormous quantities and
consequent -great cost of the marlings of that country. All the
marl (or " clay" as called in some cases) is calcareous. It lies
under the surface generally of every field, and at no great depth,
and sometimes forms the surface soil. Of course the access to
and working the marl could not well be cheaper. Yet so heavy
are the usual dressings, 3000 to more than 10,000 bushels to the
statute acre, that the improvement is very costly. Actual expendi-
tures are stated ranging from $35 to $65 the acre, for a single
marling, at short distances and with the other usual facilities of the
locality. We might safely infer that these great labours are not
necessary or even useful for the purpose of furnishing lime to the
soil; and still less if to a soil already calcareous. And of the
correctness of this inference the author leaves no doubt in the fol-
lowing subsequent passage of his Report : —

" Undoubtedly the calcareous matter contained in either marl [i. e. the
"richer marl" having 40 per cent, or more, or the "clay," of 20 or 22
per cent, of carbonate of lime], is of the highest importance ; but obviat-
ing the natural deficiencies of the soil, by adding sand to clay, or clay to
Band, is of more consequence than the mere calcareous stimulus, which
might be obtained at a much lighter expense" [by liming].

26. Of the agricultural character of the lands on the " new red
sand-stone formation" (which includes the red marl land of Lan-
cashire), Morton says —

" In Devon and Somersetshire, this is an unctuous friable clay, or red
marly soil of the first quality. It is friable enough for turnips, yet suffi-
ciently tenacious for beans and wheat, and produces the richest tyid most
luxuriant crops of any soil in the kingdom ; and the only manure that seems
necessary is the application of lime, with which it produces increased crops on
every repetition. The effects of lime on the red marl, are much greater iv
Somerset and Devonshire than in any other portion of the soil of this
formation.

" Wherever the red marl comes to the surface, it forms a rich red fria-
ble loam," &c. — "The nature of the soil is clay, calcareous matter or marl,
slippery and greasy when wet, and of a soapy feel when dry," &o. {Mor-
ion on Soils, 4th London ed., pp. 70, 71.)

Now whatever may be the benefits, and however great, of apply-
ing lime to these already calcareous soils (if the so called " marl"
is indeed calcareous), the operation is most certainly not that of
calxinfjj or the marling which I have recommended.

888 MARLING NOT TO MAKE SOIL CALCAREOUS.

27. The marling of Norfolk county is the most celebrated in
England for the great extent of the operation, and the great im-
provements thereby made. Yet the following passage from the
same writer will clearly show that the ordinary operation called
*' marling'^ in Norfolk is entirely different from the chemical action
I propose :

"So convinced" (says Morton, at p. 29), "are the farmers of Norfolk
and Suffolk of the value of the clay or chalk marl [both certainly calcare-
ous] as an alterative to their sandy surface, that they generally chalk or
clay their land once in eight 2/ ears at least, and sometimes oftener; and by
allowing 100 cubic yards to the acre, incur an expense of 50«. [more than
$12] per acre, for digging, wheeling, and spreading. It is solely by this
process, that the Norfolk sandy soil, which naturally was of the most
worthless kind, and produced nothing but heath and bent, for a few starv-
ing sheep, is now converted into good sandy loam, which yields large crops
of turnips, barley, and wheat."

Now the first application certainly included the chemical opera-
tion which I call marling (or calxing) the soil — if it was not before
calcareous. If calcareous by nature, even the first artificial appli-
cation would have no such chemical action. But much more than
half of even the first application, and all of each of the subsequent
applications, made every eight years or oftener, in great quantity
and at great expense, was merely mechanical in its action, was not
rendering the soil calcareous (it being enough so before), and, in
short, was in no respect the chemical process which I have defined
and recommended, as marling. ,We may infer that in all these
later applications, the carbonate of lime in the marl produced no
chemical effect, and acted only mechanically, if at all ', and that it
was the clay that acted most beneficially, and altogether mechani-
cally.

28. " In Hampshire and Berks, 2880 bushels per acre [of chalk, nearly
pure carbonate of lime] are applied with great advantage, at the expense
of 42s." [Morton on Soils, p. 154.)

29. There can be no higher authority than Sir Humphrey Davy*s,
for established scientific opinions, at the time he wrote, as to the
characters of soils and mineral manures. His ^^ Lectures on Agri-
cultural Chemistry'' contain the following passage — which with
others of similar import remained unaltered in his latest published
edition : —

*' Chalk and marl, or carbonate of lime, will only improve ike texture of a
soil, or its relation to absorption; it acts merely as one of its earthy ingre-
dients." {Ayr. Chem. 4th London ed. of 1835, Lecture vii.)

Of course, neither this illustrious chemist, nor Professor John
Davy, who issued, with his notes, this edition of his then deceased
brother's great work, could have had any conception of the chemi-
cal action of carbonate of lime, when applied in such small quan-

ERRORS OF SINCLAIR. 389

titles as merely to make its presence evident to the analyzer, in a
soil before entirely deficient.

30. The next following quotation offers the most remarkable
evidence of erroneous opinions of the chemical action of different
mineral manures, uttered by a modern author of the highest repu-
tation as a scientific agriculturist. Sir John Sinclair was a volu-
minous and able writer. Presiding over the British Board of Agri-
culture, he mainly directed its operations, and of course was fami-
liar with all the lights of British agriculture brought together in
the published reports of all the agricultural surveys of the counties
of Great Britain and Ireland. Moreover, the professed object of
his latest work, the *^ Code of Agriculture" was to present a
digest of all the valuable facts and instructions elicited by all those
voluminous surveys and reports, and tested and established by judi-
cious and authoritative approval. Yet in the 5th London edition
of his " Code of Agriculture," as late as 1832, and with numerous
recent additions and improvements to the work, the following pas-
sages stand in an article with the title below : —

"On bones as a manure, and on the use of shells, shell-marl and coral
for the same beneficial purposes."

"Were the advantages of the discovery restricted to the use of bones

alone, as they might possibly be exhausted, or raised in price, it would be
less important ; but fortunately the shells of oysters, and other fish, are
found to be equally effectual. Shell marl also, which abounds in many parts
of the kingdom, may be applied to similar purposes ; and coral, the banks
of which are abundant even on our own coasts, is found to be equally use-
ful. In short, it is impossible to foresee what may be the ultimate results
of this neiv source of improvement, for by a small quantity [25 bushels to
the acre, as elsewhere directed] of pounded bones or shells, great crops of
turnips may be raised ; and with the manure which these turnips produce,
abundant crops of corn may be obtained even on the poorest soils, with the
aid of a judicious rotation." (Code of Agr., 5th Lon. ed. p. 141, Appendix.)
* * * "As bones are likely to become a scarce article, it is a most fortu-
nate circumstance that the sliells of oysters and other shell-fish, when propci'ly
reduced in size, have been found equally useful as a manure. Their utility
would be much increased if they were sprinkled with sulphuric acid, by
the addition of which they would be converted into gypsum." (p. 146.)

Thus, the distinguished ' author, as late as 1832, asserts that
substances whose manuring principles are almost exclusively com-
posed of carbonate of lime, will serve to substitute, and act alike
and as effectually, as those which are almost exclusively composed
of phosphate of lime (and of fatty and ^latinous animal matter,
if these remain) ; and then recommends, as still better, the con-
verting the carbonate to the sulphate of lime or gypsum ! This
last-named manure, moreover, has not been found of benefit but in
few cases in England. It is unnecessary to expose, by further com-
ments, this confounding of the action and effects of three manur-
ing substances, all valuable in their places, yet each very different iu
action from the others.
33*

890 MARLING OF NORFOLK.

31. The means of ameliorating the texture of chalky soils, are either by

the application of clayey and sandy loams, pure clay, or marl." — "The
Qhalk stratum sometimes lies upon a thick vein of black tenacious marl,
of a rich quality, which ought to be dug up and mixed with the chalk," —
Code of Agriculture, p. 19.

32. Dickson's Farmer's Companion. — The author recommends
"argiHaceous marl" for the improvement of chalky soils; and for
sandy soils, "where the calcareous principle is in sufl&cient abund-
ance, argillaceous marlj and clayey loams/' are recommended as
manures.

33. " Chalky loam. The best manure for this soil is clay, or argillaceous
marl, if clay cannot be had ; because this soil is defective principally in
the argillaceous ingredient," — Kirwan on Manures, p. 80.

The evident intention and effect of the marling recommended in
all the three last extracts^ is to diminish the proportion of calcare-
ous earth in the soil.

34. In a Traveller's Notes of an agricultural tour in England,
in 1811, which is published in the third volume of the Edinburgh
Farmers' Magazine, the following passages relate to Mr. Coke's
estate, Holkham, and to Norfolk generally.

"Holkham. — The soil here is naturally very poor, being a mixture of
sand, chalk, and flint stones, with apparently little mixture of argillaceous
earth — the sub-soil, chalk or lime-stone everywhere." p. 486. "As the soil
of the territory [of Norfolk generally] through which I passed, seems to
have a sufficient mixture of calcareous earth naturally, I learn they do not of-
ten lime their lands ; but clay marl has been found to have the most bene-
ficial consequences on most of the Norfolk soils." p. 487.

35. "In Norfolk, they seem to value clay more than marl, probably be-
cause their sandy soils already contain calcareous parts." — Kinvan on Ma-
nures, p. 87.

From this and the preceding quotation it would follow, that the
great and celebrated improvements in Norfolk, made by marling,
had actually operated to lessen the calcareous pro])ortion of the soil,
instead of increasing it. Or, otherwise (as may be deduced from
what will follow), if so scientific and diligent an inquirer as Kir-
wan was deceived on this very important point, it furnishes addi-
tional proof of the impossibility of drawing correct conclusions on
this subject from European books — when it is left doubtful, whether
the most extensive, the most profitable, and the most celebrated
improvements by "marling" in Europe, have in fact served to
make the soil more or less calcareous.

If the "clay marl" offered above (4) by Stephens as a fair
average, and which contained only 8.40 per cent, of carbonate of
lime, is indeed as rich as the "clay marls" or "clays" spoken of
in the latter extracts, it would convert the doubt to certainty, that
many soils in England were more calcareous than such marl ; and
that its application (though truly a calcareous manure), served often

CALCAREOUS CLAYS OP NEW YORK. 391

to lessen rather than to increase the previous calcareous constitu-
tion of the soil.

36. In connexion with this statement of the poor ^^clay marls" of
Britain, it is worthy of notice that of six kinds of '' clay'^ (not
*^ clay marls/' but presented simply as clays), of New York, ana-
lyzed and reported by Professor Emmons (and quoted in Browne's
Muck Book), the calcareous proportion in five was either nearly as
large, or larger, than in the above stated British " clay marl." The
specimens reported by Professor Emmons were as follows : —
"Tertiary or Albany clay, contains carbonate of lime per cent. . 8.00
Niagara clay . . . . . . . . . .14.62

Cayii^a clay 16.48

Adonirach clay . 0.94

Brick (?) clay, near Caldwell 8.92

Reddish clay of Christian Hollow 8.29"

JBrowne's Much Book (1852).

All but one of these New York "clays" would be "clay marls"
in Britain, according to Stephens, the latest and a high British
authority.

Most of the extracts which I have presented, are from British
agriculturists of high character and authority. If such writers as
these, while giving long and (in some respects) minute statements
of marl and marling, omit to tell, or leave their readers to doubt,
whether the manure or the soil is the most calcareous — or what
proportion of calcareous earth, or whether any is present in
either — then have I fully established that the American reader
who may attempt to draw instruction from such sources, as to the
operation, effects, and profits of either marl or calcareous manures
in general, will be more apt to be deceived and misled than
enlightened.

I have now to refer to an author, whose works, well known as
they may be to others, had not come under my view until after the
earliest publication of most of the foregoing extracts. Otherwise,
Marshall would have been stated as an exception to the general
silence of British authors as to the true and precise nature of what
they treated of as ma?-!. But though he has not been, like others,
so fa»lty as to leave in doubt what was the character and value of
the marls of which he spoke, and the nature of their operation on
the soils to which they were applied, still no other writer furnishes
stronger proof of the general ignorance and disregard of the nature
of marls and calcareous manures, and of their mode of operation ;
and even the author himself is not free from the same charge, as
will be shown. I shall quote the more at length from Marshall,
because he presents the strongest opposition to what I have stated
as to the general purport of publications on marling ; and also,
because whatever may be their character, there is much to interest
the reader in his accounts of the opinions and practices of those

392 Marshall's statements.

who have used Ccalcareous manures longest and most extensively,
although without knowing what they were doing.

In his ^^ Rural EconoTYi}/ of Norfolk," the "marls'^ and "clays"
most used in the celebrated improvements of that county are mi-
nutely described, and the chemical composition stated, showing that
both are highly calcareous. Of the " marls'^ or chalks, most used
for manure in Norfolk, he analyzed three specimens, and one of
clay, and found the proportions of pure calcareous matter as
follows : —

Chalk marl of Thorp-market, contained, per cent. . . 85
Soft chalk of Thorp-next-Norwich, . . . .98

Hard chalk of Swaffham, almost pure, — nearly . . 100
Clay marl of Hemsby ....... 43

37. Of these he spoke previously and in general terms, thus :
"The central and northern parts of the district abound, universally, with
a whitish-coloured chalk marl ; while the Fleg hundreds, and the eastern
coast, are equally fortunate in a gray-coloured clay marl. The first has,
in all probability, been in use as a manure many centuries ; there are oaks
of considerable size now going to decay in pits which have obviously been
heretofore in use, and which, perhaps, still remain in use, as marl-pits.

" The use of clay marl, as a manure, seems to be a much later discovery;
even yet, there are farmers who are blind to its good effect ; because it is
not marl, but "clay;" by which name it is universally known. The name,
however, would be a thing of no import, were it not indiscriminately ap-
plied to unctuous earths in general, whether they contain, or not, any por-
tion of calcareous matter. Nothing is "marl" which is not white ; for,
notwithstanding the county has been so long and so largely indebted to its
fertilizing quality, her husbandmen, even in this enlightened age, remain
totally ignorant of its distinguishing properties ; through which want of
information much labour and expense is frequently thrown away. One
man, seeing the good effect of the Fleg clay, for instance, concludes that
all clays are fertile, and finding a bed of strong brick earth upon his farm,
falls to work, at a great expense, to "claying" — while another, observing
this man's miscarriage, concludes that all clays are unprofitable ; and, in
congequence, is at an expense, equally ill applied, of fetching "marl" fi-om
a. great distance ; while he has, perhaps, in his own farm, if judiciously
sought after, an earth of a quality equally fertilizing with that he is throw-
ing away his time and his money in fetching. — MarshalVs Norfolk, vol. i.,
p. 16.

Yet it is remarkable, that Marshall should not have intiihated
whether the Norfolk soils were naturally calcareous (as the two
writers just before quoted declare) or not ; and therefore we are
still left to guess whether these manures served to increase the
calcareous quality of soils already possessing that quality in a high
degree, or to give it to soils devoid of it before.

Other passages will now be quoted from the same, and from
other similar works of Marshall's, to show the prevailing ignorance
of the ingredients and operation of the marls, sometimes prized
and sometimes contemned, with as little reason in the one case as
the other, by farmers in various parts of England.

MARLS AND CLAYS OP NORFOLK. 893

X

88. " The principal part of his estate, howeyer, is of a much shallower
soil, not deeper than the plough goes ; and its present very amazing fer-
tility he ascribes in a great measure to his having clayed it. Indeed, to
this species of improvement the fertility of the Fleg Hundred is allowed to
be principally owing.

"Mr. F. gave me an opportunity of examining his clay pit, which is very
commodious ; the uncallow [i. e. overlying earth] is trifling, and the depth
of the bed or jam he has not been able to ascertain. It is worked, at pre-
sent, about ten or twelve feet deep. The colour of the fossil, when moist,
is dark brown, interspersed with specks of white, and dries to a colour
lighter than that of fuller's earth ; on being exposed to the air, it breaks
into small die-like pieces,

" From Mr. F.'s account of the manner of its acting, and more particu-
larly from its appearance, I judged it to be a brown marl, rather than a
clay ; and, on trying it in acid, it proves to be strongly calcareous ; effer-
vescing, and hissing more violently than most of the white marls of this
neighbourhood : and what is still more interesting, the Ilemsby clay is
equally turbulent in acid as the Norwich marl, which is brought by water
forty miles into thi» country, at the excessive expense of four shillings a
load upon the staith ; besides the land carriage. [The strength of this
Hemsby clay is stated above.]

"It is somewhat extraordinary that Mr. F., sensible and intelligent as
he is, should be entirely unacquainted with this quality of his clay ; a cir-
cumstance, however, the less to be wondered at, as the Norfolk farmers, in
general, are equally uninformed of the nature and properties of marl." —
MarshalVs Norfolk, vol, ii., p. 192,

The following is a remarkable instance, in a particular district,
of a clay very poor in calcareous matter, being considered and used
as valuable manure, and a very rich, marl equally accessible, being
deemed inferior.

39. " The marl is either an adulterate chalk, found near the foot of the
chalky steeps of the West Downs, lying between the chalk rock and the
Maam soil, partaking of them both — in truth, a marl of the first quality —
or a sort of blue mud, or clay, dug out of the area of this district, par-
ticularly, I believe, on the south side of the river. This is said to have
been set on with good effect, while the foi-mer is spoken of as of less
value ; whereas, the white is more than three-fourths of it calcareous ;
while the blue does not contain ten grains, per cent?, of calcareous mat-
ter.— Marshall's Southern Counties, p. 175.

There have before been given some extracts from this author,
showing that sundry other valued '^ marls'^ (so called) were
scarcely at all calcareous. Whatever manuring effects all these
have, must be owing to some other and unknown ingredient.

The first extracts from Marshall (just referred to) suggested a
remark, which ought to have been made earlier. When there is
so much general ignorance prevailing among practical farmers as
to what they call marl, it cannot be expected that the most intelli-
gent writers can be correct, when attempting to record their prac-
tices. When Arthur Young, for example, reports the effects of
marl in fifty different localities, as known from the practice of
several hundreds of individuals, it must be inferred that he uses

891 - SEA SAND.

the term, generally, as they did from whom hia information was
gathered, and in very few cases, if at all, as learned by his own
analyses. Therefore, it may well be doubted whether the uncertainty
as to the character of marl does not extend very generally to even
the most scientific writers on agriculture.

As some of the foregoing extracts exhibit the use of ^' marls"
(so called) destitute of calcareous earth, so the following shows,
under the name of sea sand, a manure which is in its chemical
qualities a rich marl (in our sense) or calcareous manure.

40. ** Sea sand. This has been a manure of the district, beyond memory
or tradition. There are two species still in use : the one bearing the ordi-
nary appearances of sea sand, as found at the mouths of rivers ; namely a
compound of the common sand and mud ; the other appears to the eye
clean fragments of broken shells without mixture ; resembling, in colour
and particles, clean-dressed bran of wheat.

"By analysis, one hundred grains of the former contain about thirty
grains of common silicious sea sand, with a few grains of fine silt ov mud ;
the rest is calcareous earth mixed with the animal matter of marine shells.

"One hundred grains of the latter contain eighty-five grains of the mat-
ter of shells, and fifteen grains of an earthy substance, which resembles, in
colour and particles, minute fragments of burnt clay or common red brick-

" These sands are raised in diflFerent parts of Plymouth Sound, or in the
harbour ; and are carried up the estuaries in barges ; and from these on
horseback, perhaps five or six miles into the country ; of coui'se at a very
great expense, yet without discrimination, by men in general, as to their
specific qualities. The shelly kind, no doubt, brought them into repute,
and induced landlords to bind their tenants to the use of them ; but with-
out specifying the sort — and the bargemen, of course, bring such as they
can raise and convey at the least labour and expense. It is probable that
the specimen first mentioned, is above par, as to quality : I have seen sand
of a much cleaner appearance, travelling towards the fields of this quarter
of the country ; and near Beddiford, in North Devonshire, I collected a
specimen under the operation of "melling" with mould, which contains
eighty grains per cent, of clean silicious sand!'' — MarshaWs We»t of En§-
la7id, vol. i., p. 154.

It might be inferred from all these proofs of MarshalFs know-
ledge of calcareous earth constituting the real value of marls, that
he could scarcely miss the obvious corollary to that proposition,
that the valuable operation of calcareous manures is to render soils
calcareous, and that the knowledge of the nature of the manure
and the soil would sufficiently indicate when the application of the
one to the other is judicious or not. But the following expres-
sion of opinion (^Marshall's Yorkshire, vol. i., p. 377) is not only
strongly opposed to those deductions, but to the general purport
of all his truths which I have before quoted.

41. "Nothing at present but comparative experiments can determine
the value of a given lime, to a given soil ; and no man can with common
prudence lime any land upon a large scale, until a moral certainty of im-
provement has been established by experience."

If this be true, then indeed is there no true or known theory, or

l^ATEST ENGLISH ERRORS. 395

establisbed principles or precepts, for applying either lime or any
calcareous manure. It amounts to saying, that every new applica-
tion is a mere experiment, the result of which cannot even be con-
jectured from any facts previously known of other soils and other
manures.

42. The next quotation, which is from an editorial article in the
Farmers^ Journal of July 28, 1823, shows that the old opinion
still prevails, that marl is profitable only on sandy lands; which
opinion carries with it the certain inference that it is the argillaceous
quality, rather than the calcareous, that operates. The editor is re-
marking on a new agricultural compilation by a Mr. Elkinson, and
ridiculing the author for his solemn annunciation of the truism
(in the editor's opinion), that ^^ marling on sand is more useful than
on clay land." The reputation of Mr. Elkinson, says the editor,
" may remain undisturbed among the farmers of Lincolnshire for a long
time, who may never have chanced to meet with the old proverb, or have
taken a journey into the sandy district of Norfolk. We really do not know
whether it be as old as Jarvais Markham or not : but we have seen the
following lines in black letter : —

He that marls sand, may buy land ;

He that marls moss, shall have loss ;

He that marls clay, throws all away!"

The editor then passes to a subject on which his admitted igno-
rance serves to prove that the improvement gained by marling
could not be simply the making a soil calcareous — for, upon that
ground, when marl has once been plentifully given, and the land
afterwards worked poor, there can be neither reason nor profit in a
second marling. Yet, as if the mode of operation was altogether
unknown, this passage follows :

"It was once asked of the editor by a very good practical Norfolk far-
ifier, ' whether land which had been once marled and worn out would re-
ceive the same benefit from a second marling?' It was answered, that an
experiment made on one field, or on one acre, would decide the point, but
conjecture led to nothing conclusive. It has often been observed that loose
land, after having been marled and out-cropped, deposited its marl in the
Bub-soil, which therefore became more retentive [of water] ; and it has
been suggested, that deep ploughing ought to be tried, to bring this marl
again to the top. We hope that the point here in question has before now
been settled by practice in both ways ; though at the above period (about
1806), such facts had not reached the gentleman alluded to, although a
very intelligent man."

There are copious descriptions of marl, and accounts of its use
and operation in several modern French works which I have seen
only since the first publication of this essay.* In all of these,
marl is correctly described, as being composed of carbonate of lime

* "Cours Complet," &c., par I'Abb^ Rozier; *'Maison Rustique, &c."
<^Essai sur la Marne," par M. Puvia.

396 FOSSIL SHELL BEDS IN EUROPE.

and clay, or as what I have distinguished as true marl. Neither
in these very minute descriptions (nor in any others known to me),
are shells mentioned as forming either a universal or general con-
stituent part of ordinary marls; or as having furnished directly and
immediately the main supply of the carbonate of lime of ordinary
and true marls. It is true that shells, or their fragments, are men-
tioned as being sometimes contained ; but these may be presumed
to be accidental ingredients. They are either land shells (and
sometimes so described) swept from the surface of the calcareous
lands from which the essential materials of the marl were brought
in the floods of turbid water; or in other cases, shells of fresh-
water molluscs which lived in the ancient lakes under which the
marl was deposited, and of course, the shells of such dead animals
would be enveloped in the marl, though not necessarily or properly
belonging to it.

Again : " Shell marl" is mentioned by sundry authors, but this
is even a more different formation from traie marl than it is from
our fossil shells. Its peculiar character was stated above (page
374). This is the ^' shell marl'^ to which Sir John Sinclair refers
above.

If any one can still suppose that these European writers, when
speaking of marl, could possibly mean to include such beds as ours,
or would so include them, if known there, I have a sufficient answer
ready in the fact that such beds of fossil shells as are here called
marl exist in Europe and in great extent — that they were known
to and were described by authors who wrote most extensively on
marl — and that in no case have they been termed or considered as
marl.

Many and extensive beds of fossil marine shells are known to
exist in Europe, which, in their general features, physical and
chemical, and fitness for agricultural uses, must be similar to ours.
Of these deposits, both in England and France, there have been
applications to the land, though to very limited extent compara-
tively, and the fertilizing value is recognised. Scientific observers,
of course, know that these beds agree with true marl in the im-
portant and main characteristic of being in part composed of car-
bonate of lime. Still, in the only three agricultural notices of these
beds of fossil shells which I have seen, and all are from scientific
agriculturists, this substance is not called marl ; and it is noticed
under a different head, and treated as if a different manure. The
practical cultivators who have applied it, doubtless deemed this
manure as different from marl in substance and qualities as in
name.

One of the notices referred to has already been quoted above,
(20, page 383), in the words of Arthur Young, concerning the
Suffolk ^^ cragy^ the name used for this deposit in England. This

FALUNS AND PALUNAGE OF TOURAINE. 397

scant notice is all that is taken of this kind of fossil mannre, in that
author's voluminous Agricultural Survey of Suffolk, and of which
a large portion is devoted to marl and marling. It is manifest
from his expressions, that neither Young nor the Suffolk farmers
had any idea of this '^ crag" being marl.

The other and more full accounts are by French authors. The
latest is by M. Puvis, who has written so extensively on lime and
marl, and whose views of calcareous manures are worth more than
those of any other European writer, previous to the general digest
in the recent Lectures of Prof. Johnston. Puvis' remarks on this
subject, of which all will be translated and given below, follow his
Essay on Marl in the Annales, but as one of several different though
connected subjects — under the different divisions and titles of
" Platras, or remains of demolished buildings" — " Falunage, or
use of shells as an improver" — ""G-ypsum" — and '^ Wood-ashes.'^
Under the head oifalunage the following remarks occur :

"43. Of Falunage, or the use of shells, as an improver of soil.

" The name/aZ?ms has been given to those beds of fossil shells which are
found, whether on the borders of the sea, or in the interior of the land. In
certain places i\\Qfalun, is used under the name of shell marl;* but it is Only
the falun of Touraine [in France], of which the use in agriculture is well
known. The faluniere there forms a bed of three leagues in length, and of
variable width and thickness. The falun is taken out from many feet in
depth ; and as there is much water, it is obtained by tha force of many
hands, of which some draw off the water while others get out i\xQ falun. It
is put on the land at from 30 to 60 wagon loads to the hectare [nearly 2 J
acres] according to the nature of the soil. Its action appears at least as
eflBcacious as that of marl ; and the effects last long.

*' They use in England a much lighter dressing ; not more than one-half
of the lightest dressing in Touraine. The particular qualities and fertilizing
forces may be different, as the beds are composed of very different families
of shells ; so that each region may be right in its practice. The duration
of a falunage in England is longer than that of marl ; and its energy is re-
newed by a compost of barn-yard manure and shells, as in regard to marl
and lime. The soil is greatly meliorated ; still more, as it seems, than by
lime or marl. It may well be true that these shell beds may in fact contain
some albuminous substances, some animal parts, which add to the effect
of the carbonate of lime, which forms the principal base of the manure.

*' There are found in France these shelly beds in many places. They are
spoken of in the environs of Dax, of Grignon (Seine-et-Oise), of Courtag-
non (in Marne) ; but the conchologists seem to have made more use of them
than the agricultui'ists. Doubtless, they are to be found in many other

* It is manifest that the author, in reporting this provincial and particu-
lar application of the name "shell marl" does not adopt it, or approve it.
He never himself uses the words marl {marne) or marling {marnage) applied
to this earth; but always falun for the substance, falunage for the applica-
tion of it as manure ; and faluniere for the bed, or deposit in its natural
place, or for the excavations therein, as understood in the next succeeding
article. E. R.
34

398 TALUNAGE IN FRANCE.

places. These deposits are one of our mineral treasures, from which we
are far from deriving proper advantages. For if using the falun at tlie
rate of 100 hectolitres to the hectare, as in England, it might be trans-
ported to a distance, either by water or land carriage. And what further
recommends its use, at least as much, the falun is not accused of having
impoverished the soil. On the contrary it is found everywhere improved."*
— Annates d' Agriculture Frangaise, 1835.

The next passages are translated extracts of the article '^ Falwn!^
in the '' Cours Gomj^let," &c., which is a joint contribution by
llozier and Cadet-de-Yaux.

44. " This name is given 'to a great body of marine remains which
exist in Touraine, over an extent of about three leagues in length, and of
less breadth. Neither the exact limits nor the depth of this bed is known.
The excavations have not been sunk lower than 20 feet, because of the
water which oozes from all sides into these falunieres. What a deposit !
What immense quantity of shells ! We may also add, what a treasure ! For
these spoils of the ocean are an excellent improver of soil.

We will then merely consider the falun as an improver.

After being extracted from the pit, suffered to drain and become dry, it is
spread on the fields the same as marl ; and the proportion varies according
to the quality of the lands on which it is spread — in the same manner as
of marl.

" Here is the difference which exists between these two improvers: Marl
is a calcareous earth, of the same nature as the falun, but it is mixed with
sand and argil ; so that the first thing to do when one marls a field is to
know well the [degree of purity of the] marl. This knowledge is easy to
acquire by the most simple analysis. ..,,...

. . . . The falun is pure calcareous earth ; but which contains more
or less of the principles which were united to the calcareous earth in the
formation of the shells. Unless constantly soaked in water, it may not
have lost these principles. Then the falun can no longer be considered as

a pure calcareous earth, and destined to act only mechanically

We will observe that the falun has, in common with marl, no influence on
the fertility of the field which receives it until the second year ; and the
effects of both these earths become enfeebled at length ; when it is neces-
sary to apply them again."

I have omitted of the last article as much as could be separated
of the superfluous, useless, and mistaken statements — and there is
not much else. But all is left that refers to what I designed to
show, i. e., that the authors had no thought that the falun was
marl.

This last description of the falun of Touraine goes to show that
the mass was of shells or their fragments alone, or without the

* This ground of superior value assumed for the falun, I take as indirect
evidence, in addition to the author's direct assertion, that this kind of
manure has been but little used, or that little is known of the effects. The
use of calcareous manures in Europe has been almost entirely empirical,
and not directed by any theory, or rational rules. Hence damage has often
been done by improper applications of both lime and marl ; and if the falun
has been harmless, rich and abundant as it is, and ejisy to apply, it must
be because of its very limited use. E. R.

OLD VIEWS OF MARL OF VIRGINIA. 399

usual admixture of sand or clay. I have worked a particular layer
nearly as pure, and which had the same disadvantage of water
pouring in through the very open texture of the broken shells.
There is an extensive bed of as pure and unmixed fossil shells, near
to the surface of the earth, and there quite dry, near the northern
limit of sea-coast of South Carolina.*

45. The next evidence is from a report of the Rev. John
Clayton, Rector of Crofton, in Yorkshire, to the Royal Society of
England, in 1688. The writer visited Virginia, and this was the
report of his personal and somewhat scientific examinations. It
was republished in the 4th vol. of Farmers' Register. The writer
saw, with astonishment, and describes the beds of fossil shells in
the river cliffs — and though with much looseness and inaccuracy,
still there is no doubt that he included in his observations not only
the actual beds of loose oyster shells, but the petrified oyster shells in
other places, and also the beds of other and various fossil sea shells,
which since have obtained in Virginia the provincial term of marl.
For though he c-alls all of them " oyster shells,^^ it is manifest that
he also referred to the sea shells, as he particularly describes the
" shark's teeth" and large vertebrae which are so common in these
beds, and never known in the deposits of oyster shells alone. Now
this gentleman, from his residence, and his information, could not
possibly have been ignorant of marl in England. Yet in all his
remarks and speculations (some very wild), on these beds in Vir-
ginia, he does not call them marl, or refer to any similarity of these
beds to marl — nor even suppose any use for ours, other than that
before known, of burning the shells to make lime for oement. (See
Farmers' Register, vol. iv., pp. 642-3.)

From all the foregoing quotations and evidences, I claim that
the propositions enumerated in the beginning of this article, have
been sustained fully ; and that the following deductions must neces-
sarily be made : —

1. For centuries after marling had been recommended by Eng-
lish books on agriculture, and extensively practised by very many
farmers of England, it was not generally, if at all, understood by
either writers or farmers that calcareous earth was the all-important
or even an essential ingredient of marl, as a manuring agent ; and
many clays used for and as marl, certainly contained no carbonate
of lime.

2. Though more lately, English writers have taught correctly
that marl is calcareous, and also (generally) that the value of the
manure depends mainly on the lime contained, still the previous

* Described in the supplement to my Report of the Agricultural Survey
of South Carolina. The deposit is on and near Price's creek, in Horry — and
is of the potit-pliocene division. E. R.

400 MARL NOT VALUED FORMERLY.

ignorance continued to prevail among the more illiterate farmers ;
and even some writers of reputation, to recent times, have shown
in their expressions the influence remaining of the previous and
universal ignorance on this subject. Long after these more correct
views of the constitution and true source of value of marl had been
published by the then most enlightened writers, their readers did
not learn from them enough of their truth to dispel the previously
long existing and prevailing erroneous views. Hence the " soapy
feel,^' and clayey constitution, and the crumbling in water, still
continued to be regarded by all as essential qualities and important
values of any manure operating as marl ; and comparatively little
importance was attached to the calcareous ingredient — even when
that was not entirely disregarded or unknown.

Hence Bordley, an extensive reader of the best and newest
English agricultural books, himself an agricultural author, and
moreover a practical and wealthy farmer, on the " marl region"
(now so known) of Maryland, did not learn from his English
teachers and guides that marl was necessarily calcareous; and never
suspected that the beds of fossil shells, so abundant in his own
neighbourhood (if not on his own farm), either were marl, or had
any value as manure. We may also infer that our great Virginian
agriculturist, John Taylor of Caroline, a much later writer than
Bordley, and also well acquainted with English agricultural authors,
had learned nothing more either of true marl, or of our beds of
fossil shells being (as indicated by the vulgar name), identical with
marl. Further : Philip Tabb, of Toddsbury, in Gloucester county,
was one of the earliest good farmers of Virginia, and deservedly
the most celebrated in his time for his judicious management, and
for his success in improving his farm and its productions. Yet
from all his lights, and doubtless his general knowledge of English
marling, he never suspected to be marl, and never thought of using
as such, or for manure, the bed of what is now called marl, which
underlies the whole farm, and is generally accessible within 4 or 5
feet of the surface. It has been only in latter days, that this most
abundant and easily accessible bed has been opened, and used
largely and advantageously as manure for this farm.

3. And further : No person, deriving his information solely from
the descriptions of marl by English writers, and their remarks on
the subject, and searching for marl by aid of their directions, would
have supposed he had found the object of his search in the marine
fossil shell formation of this region — so entirely different as is this
from all the marls (true or false) described by those writers, in
outward appearance, texture, and other physical qualities always;
and in some cases there is no less difference in the more important
chemical constitution, in regard to calcareous earth being an in-
gredient or not.

MOST ANCIENT NOTICES OP MARL. 401

<> Marl and Marling of the Ancients.

I will add to these extracts, though merely as a matter of curi-
osity, the most ancient notices of marl extant, translated from the
works of Varro and Pliny, respectively nearly 1900 and 1800
years old. Their great antiquity would alone serve to invest these
statements with much interest. And it is also interesting and
amusing to observe that nearly as much was known of the proper-
ties of marl by the then barbarous Britons, more than 1800 years
ago, as by their enlightened descendants 1700 years later. For if,
in the report by Pliny, the proper names were omitted, and the
piece appeared without date or authority, it might well be supposed
to be from some one of the English publications on marl which
appeared after the middle of the last century. Pliny, and the
Gaulish and British farmers from whom his statements were indirect-
ly derived, were as ignorant of the true character and action of marl,
as were the farmers, and also most of the best agricultural writers,
as late as 1780 — but not more ignorant. Like these much later
writers, Pliny seems not to have known, or, if knowing, not to have
attached "any importance to the calcareous quality of marl; nor
was he, more than they, at all precise in distinguishing between
marl and non-calcareous clay. Still it may be inferred, from the
context, and from indirect testimony rather than the direct state-
ments of the author, that either true marl or chalk was always re-
ferred to; and of course that it was truly calcareous manure of
which he spoke. The manure referred to as being used by the
Edui and Pictones, calx, is named with sufficient exactness; and
if not lime, as rendered in the translation, it must have been car-
bonate of lime in some form, as calx properly means. But by
using the word calx in this case, and creta when chalk obviously
was meant, it seems likely that the former was designed for cal-
cined lime.

Translated from <* De Re Rustical Var. Lib. I. Cap. 7.

** In Transalpine Gaul as far as the Rhine, when I commanded the army,
I went into some regions, where neither the vine, the olive, nor apples
grew, and where they manured their fields with a white chalk dug out of
the earth [candida fossicia creta].

Translated from Plin. Nat. Hist. Lib. XVII., Cap. 5, 6, 7, 8.

** To improve land (as some conceive) by the application of rich earth to
poor, or of porous and sandy to moist and very fertile, is the work of folly.
What can he hope who pursues such practice ?

"There is another method, which was discovered in Britain and Gaul,
of fertilizing land with a kind of earth which they call marl [inarc/al.
Greater fertility is pei'coived. There is a peculiar fatness \_adeps'] of this
earth which like the glandules in bodies serves as a nucleus for increased
fertility.

" The Greeks also have not neglected this plan : for what have they failed
34*

402 pliny's account op marl and marling.

to try? A "white clay ^Candida argilla] which they use in Megaris, but
only on moist and cold soils, they call Leucargillon.

" It is proper to describe with care that used to enrich the soils of Gaul
and Britain. At first there were two kinds, but of late several others have
begun to be used as their information increased. There is the white, red,
dove- coloured, argillaceous, porous [tophacea], and sandy. Its character
is two-fold, rough or unctuous \_aspera aut pinguis]. Specimens of both are
at hand. Its effect is likewise two-fold, either to bring grain alone, or also
to nourish grass. The white porous [tophacea alba] marl nourishes grain,
and if found among springs is immensely rich. It is rough to the touch,
and if applied in too large quantities it burns the land. The next is the red
marl, which they call capnumargos, from the stone being intermixed with fine
sandy earth. The stone is crushed in the field itself, and for a few years
the stalks (of grain) are cut with difficulty on account of the pieces of stone.
Yet in consequence of its lightness it is applied at very little expense, less
than one-half the cost of the others. It is spread thin, and is thought to be
mixed with salt. Each kind once applied will last for fifty years, increasing
the product both of grain and grass.

" The white is the main variety of those which are known to be unctuous
[pi7igues]. Of this there are several kinds. The most caustic [i.iordaces-
simum] is that of which we have spoken above. Another is a kind of white
chalk [alba creta] used to -scour silver. It is brought up out of the earth,
shafts being sunk often a hundred feet deep, narrow at the mouth, but en-
larging within as in mines. This kind is principally used in Britain, and
lasts eighty years. Nor is there an instance of any one who has twice
applied it to the same land during his life. A third kind of white they
call glischromargon. It is a fuller's chalk (cretafullonia) mixed with unc-
tuous [pingui] earth, better for grass than grain, so that one crop being
taken off, before the next sowing, the richest grass can again be cut.
When it is in grain, it brings no grass in addition. It lasts thirty years,
but when too thick it stifles the land like siguinmn [old cement of terras,
gypsum, &c.]. The dove-coloured the Gauls call by their name of Egleco-
pala. It is gotten out in clods like stones, but by exposure to sun and frost
it separates into very thin laminae. This is equally rich. The sandy is
used in default of other kinds ; ir| wet, oozy [uUginosis\ places, however, it
is used even when others can be had. The Ubii are the only people we
know, who when tl^ey cultivate very rich land, manure it by digging up the
earth more than three feet deep and spreading it on to a foot's thickness
[quacunque terra infra tres pedes effossa, et pedali crassitudi/ie injecta Icdtifi-
cent]. But it does good for not rfiore than ten years.

" The Edui and Pictones* made their fields very rich with lime [calx]
which likewise is found of the greatest benefit to both olives and vines.
All marl [marga'] must be put on ploughed land ; so that its fei'tilizing pro-
perties may be quickly absorbed; and that which at first is too harsh
[aspera] and does not at once profluce an abundance of herbage [qua in
herbas non effunditur], requires a small amount of dung, or else by its fresh-
ness [novitate'] it injures the soil, and is not fertilizing till after the first
year. It is also important to note the kind of soil on which it is to be put,
A dry marl, whether the chalk [cretal or the dove-coloured [columbiiia,'] is
best adapted to a moist soil, and an unctuous marl (pinguis) to an ai'id soil,
the one quality serving to temper the other."

* The Edui and Pictones were the ancient Gaulish inhabitants of the
modern Autun and Poictiers, respectively, of France. — London Quarterly
JRevieic,

NOTE III.

THE EARLIEST KNOWN SUCCESSFUL APPLICATIONS OP FOSSIL
SHELLS AS MANURE.

The two old experiments described at pp. 114-15, though the only
applications of fossil shells known to me previous to the commence-
ment of my use of this manure, were not all that had been made,
and, which being deemed failures, had been abandoned and forgot-
ten. Another, within a few miles of my residence, was brought to
light and notice afterwards, by an old negro, who was perhaps the
only person then living who had any knowledge of the facts. After
I had found enough success in using this manure to attract to it
some attention, Mr. Thomas Cocke of Aberdeen, was one of those
who began, but still with doubt and hesitation, to use marl to some
considerable extent. One of his early applications was to his gar-
den. The old gardener opposed this, and told his master that he
knew " the stuff was good for nothing, because, when he was a boy,
his old master (Mr. Cocke's father) had used some at Bonaccord,
and it had never done the least good.'' Being asked whether he
could show the spot where this trial had been made, he answered
that he could easily, as he drove the cart which carried out the
marl. The place was immediately sought. It was on the most
elevated part of a very poor field, which had been cleared and ex-
hausted fully a century before. The marled space (a square of
about half an acre), though still poor, was at least twice as produc-
tive as the surrounding land, though a slight manuring from the
farm-yard had been applied a few years before to the surrounding
land, and omitted on this spot, which was supposed, from its
appearance, to have been the site of some former dwelling-house
and yard, of which every trace had disappeared except the perma-
nent improvement of the soil usual from that cause. A close
examination showed some fragments of the hardest shells remaining,
so as to prove that the old man had not mistaken the spot. This,
like other early applications, had been made on ground too poor for
the marl to show but very slight early effect ; and as only one kind
of operation of any manure was then thought of (that which dung
produces), it is not strange that both the master and servant should
have agreed in the opinion that the application was useless, and
that all persons who knew of the application remained under that
opinion until almost all remembrance of the experiment had been lost.

Since the printing of the previous pages in which references were
made to the earliest application of marl in Virginia, I have obtained
some further information thereupon, which, however imperfect,
may yet be interesting. In a recent conversation (1842) with
William Short, Esq., now of Philadelphia, the son of Major Wil-
liam Short who made the experiment, he told me that he well re-

(403)

404 EARLY TRIALS OP MARL.

collected wlien his father's first and accidental discovery of marl
was made on the Spring Grarden farm in Surry (in digging a ditch
across a wet swamp), and his sanguine and confident anticipations
of deriving from its use great improvement and profit. Mr. Short
further stated that he was then so young, and always so little
acquainted with agriculture, that he did not know what were the
precise facts in regard to the failure of his father's experiment and
hopes ; but he well remembers that the result was deemed an entire
failure, and that it caused total disappointment.

Such a conclusion I had supposed before being so informed. I
had also inferred, and no doubt correctly, that the supposed failure
and truly slight benefit, and the mistaken deductions from the
results, were such as have been stated. I have since written to
the present proprietor of the land, Francis Ruffin, Esq., to obtain
the latest information concerning the results of this application,
now some sixty-five years old; and the most recent effects, as
learned from him, will be here stated in connexion with the earlier,
which will be repeated.

It was before said (page 114) that this old marling (of about 10
acres) was done on poor sandy land, kept (as was the then univer-
sal course of tillage) under exhausting culture and close grazing
for many years thereafter; that from 1812 the treatment had been
lenient; and that in 1819, the superiority of the marled part was
visible, and that part of the outline could be then distinctly traced.
In 1834, Mr. F. Ruffin applied to this and some acres of adjoining
land, pine leaves at the rate of 75 one-horse cart-loads to the acre.
The benefit from this vegetable cover was so much greater on the
marled part, that the superior growth of the next crop of corn and
of the succeeding crop of wheat, " marked out the limits of the old
marling very conspicuously." The whole was sown in clover in
the spring while under wheat ; that on the marled part lived and
stood pretty well, while nearly every plant of clover on the part
not marled died in the course of the year. In 1837, the whole
field was marled, without excepting the old marled part ; and the
whole was again littered with pine leaves. The crops of corn and
wheat since have shown less improvement from these applications
on the piece thus re-marled, than on the adjoining land then marled
for the first time. Indeed, the recent and additional increase of
corn and wheat, since re-marling, has been very little. These re-
sults, early and late, are precisely such as might have been antici-
pated from the action of calcareous manures, and the condition of
this land and its management.

Another experiment of marling, made earlier than my first, by
Mr. Richard Hill, in King William county, has been heard of
since the publication of the last edition, and of which the circum-
stances were given at length at pages 22 and 27 of vol. ix. Far-

EARLY TRIALS OP MARL. 405

mcrs' Register, to which the reader is referred. It is enough here
to state, that the effects were beneficial at first; but so injurious
(because of the excessive quantity) on several succeeding crops,
that this trial also was deemed a failure, and the marling a source
of loss ; and there was no repetition of marling in that neighbour-
hood until a,bout 1820, when other and better views began there to
be first entertained.

There was also successful and continued use of this manure in
James City county, in Virginia, made earlier than mine ; and still
earlier by Mr. "John Singleton, in Talbot county, Maryland.
It appears that the early (though chance-directed) combination of
putrescent manures with marl, in both these places, served to prove
the value of the latter, and perhaps to prevent it being there also
abandoned as worthless, as in the other cases. But though the
application was continued, and with great success and profit, the
knowledge of these facts and the example extended very slowly ;
and the then want of communication among farmers kept all igno-
rant of these practices for years, except in the immediate vicinity
of the commencement of each. I have since endeavoured to ascer-
tain the time of the first applications in James City, and have been
informed that it was in 1816. Mr. Singleton's, in Maryland, were
begun as early as 1805. His own account of his practice (which
will be annexed, as an interesting statement of the earliest profitable
use of this manure), was first published in 1818, in the 4th volume
of the Memoirs of' the Philadelphia Agricultural Society (page 238).
The date of his letter is Dec. 31, 1817. My first experiment was
made the following month (Jan. 1818), but more than a year before
I met with Mr. Singleton's publication, or had heard of any appli-
cation of fossil shells, except the two failures mentioned in page 115.
But, however beneficial may have been found the operation of marl
in Talbot and in James City, it is evident, from Mr. Singleton's
letter, and from all other sources of information, that the mode of
operation remained altogether unsuspected by those who used it;
and this was perhaps the principal cause why the practice was so
slow in spreading. It is now [1835] thirty years since the first
proofs were exhibited on the land of Mr. Singleton ; yet, according
to the report of the geological survey of the lower part of Maryland
(submitted to the legislature of Maryland at its recent session of
1834-5), it appears, though the value of marl is well understood,
and much use of it made in Talbot county, and part of Queen Ann's
county, yet that almost no use has been made of it on the other and
much more extensive parts of the Eastern Shore of Maryland — and
none whatever west of the Chesapeake in that state, where it is
found in abundance. Such at least are the inferences from Dr.
Ducatel's report, though in part drawn from indirect testimony,
more than direct and particular assertions.

406 MR. singleton's marling.

The slight, and almost contemptuous manner, in which marl is
mentioned bj so well informed an agriculturist as Taylor, as late
as 1814, when his Arator was published (and which remained un-
altered in his 3d edition of 1817), proves that almost nothing was
then known of the value of this manure. All that seems to relate
to our abundant deposits of fossil shells, or to marl generally, is
contained in the two following passages : —

•' Without new accessions of vegetable matter, successive heavy dress-
ings with lime, gypsum, and even marl, have been frequently found to
terminate in impoverishment. Hence it is inferred, that minerals operate
as an excitement only to the manure furnished by the atmosphere. From
this fact results the impossibility of renovating an exhausted soil, by re-
sorting to fossils, which will expel the poor remnant of life ; and indeed
it is hardly probable that divine wisdom has lodged in the bawds of ike
earth the manure necessary for its surfaced — Arator, p. 52, 2d edition, Jialti-
niore.

" Of lime and marl we have an abundance, but experience does not enti-
tle me to say anything of either." — Id. p. 80.

From John Singleton to the Hon. Wm. TilgTiman.

*' Your first question is, ' whether what I use be marl, or soil mixed with
shells ?'

" Whether it be marl or not, I will not pretend to determine, as I have
seen no description of marl that answers exactly to it; but Mr, Tench
Tilghman informed me he had seen a description of marl used in Scotland,
exactly similar to what I use on the farm on which I reside, and which is
the improved land you mention. I have not seen the account myself.
However, this, and all mixtures of broken marine shells, of which there is
a great variety, are now denominated marl, here. What I consider the
best, and which I most use, is composed of small parts of marine shells,
chiefly scallop shell, about one-eighth of an inoh square, or somewhat
longer or smaller, with scarce any sand or soil with it: some of it seems to
be petrified, and is dug up in lumps, like stone, from four or five, to forty
or fifty pounds in weight, hard to break even with the eye of an axe, and
will remain for years, tumbled about with the plough, before it is entirely
broken to pieces, and mixed Avith the soil ; indeed you may observe it in
some parts of the bank, where the soil has been washed from it, appearing
like rock stone ; but if broken and pulverized a little, it effervesces very
much with acids. * * * * * -jfr

" I have applied it to all the soils on my farm, some of which is a cold
white clay, and wet ; others a light loam, and sandy. I find it useful to
each kind, and manure my land all over with it, without distinction, and to
advantage ; putting a smaller quantity upon the looser soils. I have applied
it as a top dressing on clover, and also where clover has not been sown,
with a view to improving the grass, and also to be satisfied whether it
would not be best for the ground, to let it lie spread on the surface, for a
year before the ground was put into cultivation. But it has not answered
my expectation. I could not perceive any advantage from that mode of
application. I now constantly apply it to the ground cultivated in corn ;
carting it out in the winter and spring, and putting on from twenty to forty
cart-loads per acre, according to the ground, and the previous quantity

MR. singleton's MARLING. 407

that had been put on, in former cultivations, dividing each load into from
four to eight small heaps, for the greater ease in spreading, according to
the size of the load. Some is put on before, and some after the ground is
broken up, but it is all worked into the soil by the cultivation of the corn,
and it never fails of considerably improving the crop of corn, as also the
ground wherever the marl is, especially in largest quantity. There is a
small green moss, and black moist appearance, on the surface of the ground,
■when not cultivated ; as you perceive about old vralls, and in sti«ong ground.
Though the preceding is the common mode in which I use the marl, I do
not think it the best ; I mix some in my farm-yard, with the farm-yard and
stable manure; and would prefer mixing and applying all that I use thus
mixed, but for the labour of double cartage which I cannot as yet accom-
plish, manuring so largely as I do. I cultivate one hundred acres yearly,
and constantly manure the whole of what I cultivate ; employing only four
carts, and four hands with the carts, which do all the manuring and cart-
ing on the farm.

"Your next question is, 'what has been my rotation of crops, and mode
of cultivating, since I have used this manure ?'

*' Since I began to use the marl, and bend my attention to improvement
by manure, I have cultivated only corn and wheat, sowing my ground in
clover, and using the plaster. Instead of cultivating all my ground in corn,
and sowing wheat on it as heretofore, I divided my cultivation into two
parts, of fifty acres each, putting one part into corn, which I was able to
accomplish manuring time enough for the cora, and making a fallow of the
other part, manuring as much of it as I could accomplish before the time
for sowing wheat ; and disregarding, in a degree, all smaller crops, which
I could not attend to, as an object, without increasing my number of hands,
and interfering with the main business. I went on in this manner, till I
found I could easily accomplish manuring one hundred acres and upwards,
per annum. Having got my ground to that state that I can risk making a
crop without manure, I am now about discarding fallow, being able to
manure my whole hundred acres time enough for croj^ping in the spring,
by beginning to manure for the next year as soon as the spring manuring
is finished. I shall in future have no wheat in fallow, but sow it after corn
and other crops, from which I am satisfied I can make more from my
ground than by naked fallow, which I always considered unprofitable,
though you made more wheat, except for the advantage of having more
time to manure. * * * * -x-

" In saving my com crop, I cut it tip without pulling it from the stalk
as usual, and cart it in all together, then husk it out, leaving the husk to
the stalk : I lay these near my feeding yard, and throw them into it twice a
day : this gives us a large quantity of strong healthy food for the cattle,
which serves them all winter, and keeps them in good condition without
any other food ; makes a large quantity of excellent manure, and a fine dry
feeding yard. As opportunity can be found, we cart marl, fuller's earth,
clay, and any good soil that is convenient, into this yard, which being
mixed with the stalks, and straw, or anything else, penning the cattle on it
through the winter and summer, instead of penning on the field, in the
common way, we have a large quantity of manure to go out in the fall, and
next winter ; it is put into the field, in the intermediate rows, between the
rows of marl, as far as it will go, and they will get mixed in the cultiva-
tion. We also convert the scouring of our ditches, the head-lands of the
fields, and all waste-ground that, we can, into manure, by carting litter,
from the woods, yard manure, or litter, &c., and mixing with them; so
that I can nearly, or quite, now, accomplish making farm-yard and this

408 MR. singleton's maeling.

kind of manure, sufficient to go over my whole hundred acres annually.
For the last two years, I have made more manure than I could accompliish
or eflFect carrying out, though I have manured from ten to twenty acres
more than my hundred, each year, with part marl and part farm-yard, but
not the whole with both, as I hope to bo able to do in future ; but it will
be necessary to increase my carting force to effect it, and I clearly see I
can raise sufficient manure for the purpose ; hei^etofore I have manured my
corn ground*, fifty acres, with marl, and my fallow with part farm-yard
manure, and part marl, as mentioned before ; so that you will perceive the
improvement made on my soil has not been efl'ected by marl alone, but in
conjunction with fsirm-yard manure, clover, and plaster, and by making it a
point to manure with something all the ground I put into cultivation; so
that every time I cultivated a field, that field was improved, and not in any
degree impoverished by the cultivation. By this means, and the Divine as-
sistance, I have effected that improvement of my farm, which is so very
striking to the observation of every person acquainted vrith it. -Jt * ■*
"In August, 1805, in digging down a bank on the side of a cove, for the
purpose of making a causeway, I observed a shelly appearance, which it
struck me might improve clay soil ; I took some of it immediately to the
house, and putting it into a glass, with vinegar, found it effervesced very
much ; this determined me to try it as a manure ; accordingly, in Septem-
ber, I carted out about eighty cart-loads, and put it on a piece of ground,
fallow, preparing for wheat, trying it in different proportions, at the rate
of from twenty-seven to about a hundred loads per acre, and the ground
was sown in Avheat. I could not, myself, be satisfied that there was any
difference through the winter and spring, although General Lloyd, who
was viewing it with me in the spring, thought he could pei-ceive some dif-
ference in favour of the marl ; but at harvest time, the Avheat, though not
more luxuriant in growth, or better head, was considerably thicker on the
ground ; and after the wheat was taken off, the ground where the marl had
been put was set with white clover, no clover being on the ground on
either side of it. The next year, 1806, I discovered it in the drain into
the head of the cove, which I immediately ditched, and from the ditch put
out seven hundred loads, on the fallow ground. The effect, as to the wheat
and clover, was the same (this was put, for experiment, at the rate of from
forty to a hundred and twenty cart-loads per acre), tlaough the marl was
not of the same kind as the other, but more mixed with sand and surface
soil, being taken from ihe low ground, by ditching, and all mixed together.
I also tried it on corn ground, spread out as above mentioned, and found
the effect immediate, as to the corn ; and in the same manner as above
described, as to the wheat sown on the corn ground. This induced me to
persevere in the use of it, which I have done ever since, adopting the mode
I mentioned before, and putting it at first from forty to seventy loads per
acre, till I have now come down as low as eighteen or twenty loads per acre,
going the third time over the ground with it." * * * *

NOTE IV.

FIRST VIEWS WHICH LED TO MARLING IN PRINCE GEORGE COUNTY.
[From tlie Farmers* Register^ Nov. 1839, icitJi additions.)

Among the persons who have read with interest the " Essay on
Calcareous Manures/' and have received as sound the novel theory
and doctrines there maintained, several have expressed^their curi-
osity which had been excited to learn the earliest facts, or the train
of reasoning, which led to the suggestion of the causes of the de-
fect of naturally barren soils, and the remedy. Such inquiries
have been made of the writer by persons of investigating and well
informed minds, tTut of very different education and pursuits; and
they were pleased to say, in regard to the concise verbal answers
made to their inquiries, that they deemed the details likely to be
interesting to many, and that if given to the public, they might
serve better to induce the consideration and enforcement of the
doctrines, than had been done by the mere arguments which had
been already published, convincing as they considered these argu-
ments to be.

Though, without these reasons and solicitations, the writer might
have still refrained from touching this subject, it was not that he
had not held the same opinion, and, except in his own case, would
have urged the same course. It is certain, that the tracing of the
steps by which any new discovery or improvement has been reached,
must always be interesting in proportion to the admitted importance
of the results; and, indeed, such a statement seems almost necessary
to induce the reader to accompany the author from his first premises
to the remote conclusion, and which otherwise is only reached
through a devious and tedious passage, and by a course of reason-
ing which is wanting in interest, because the application and
tendency'' of the arguments and proofs are not seen when they are
first presented. The objection which restrained the writer from
before pursuing a course which he would have highly approved in
others, was, that such a narrative of opinions and facts would be
entirely a personal narrative, and therefore obnoxious to the charge
of egotism throughout. The statement of the reasoning which led
to the successful use of fossil shells on the poor lands of lower
Virginia, would be incomplete if not accompanied by a narrative
of early labours, and the early as well as latest results and effects.
In the whole of this, there would be scarcely anything but state-
ments of what the writer thought, and reasoned, and performed.
But the subject must be so treated, or not at all; and having con-
sented to give the narrative, the writer will throw aside all scruples
and objections, and endeavour to enter as much into detail, as he,
if a reader of others' agricultural improvements and practical ope-
rations, would desire there to find.

35 ' (409)

410 THE author's early views

With the beginning of the year 1813, when barely nineteen years
of age, the easy indulgence of my guardian gave to me the posses-
sion and direction of my property ; which consisted of the Coggins
Point farm, with the necessary and yet very insufficient stock of
every kind. It is scarcely necessary to add that, at my very early
commencement, I was totally ignorant of practical agriculture;
and such would have been the case, according to the then and now
usual want of training of farmers of Virginia, even if my farming
labours had been postponed to a mature age. But I had always
been fond of reading for amusement, and the few books on agri-
culture (then very scarce in this country) which I had met with,
had been studied, merely for the pleasure they afforded, at a still
earlier time of my boyhood. The earliest known of these works
was an English book, in four volumes, the " Complete Body of
Husbandry,'^ of which I have not seen the only known copy since
I was fifteen years old. This work was probably a mere compila-
tion, and of little value or authority ; but it gave me a fondness
for agricultural studies, and filled my head with notions which were,
even if proper in England, totally unsuitable to this country.
^' Bordley's Husbandry" next fell into my hands, and its contents
were as greedily devoured. This was indeed written in America,
and by an American cultivator; but as he drew almost all his
notions from English writers, his work is essentially also of foreign
materials.

Thus prepared, I commenced farming, ignorant indeed, but not
in my own conceit. The agriculture of my neighbourhood, like
all that I had ever witnessed, was wretched in execution, and as
erroneous as well could be in system, whether subjected to the test
of sound doctrine, or the improper notions which I had formed from
English writers. I was right in condemning the general practice
of my neighbours; but decidedly mistaken in my self-satisfied
estimate of my own better information and plans.

Just about the time that my business as a cultivator was com-
menced. Col. John Taylor's ^^Arator'' was published; and never
has any book on agi-iculture been received with so much enthusiastic
applause, nor has any other had such wide-spread early effects in
affecting opinion, and stimulating to exertion and attempts for im-
provement. The ground had before no occupant, and therefore
this work had to contend with no rival. The larger land-owners,
of lower Virginia especially, had previously treated their own pro-
per employment, and their only source of income, with total
neglect ; and very few country gentlemen took any personal and
regular direction of their farming operations. It was considered
enough for them to hire overseers (and that class then was greatly
inferior in grade and respectability to what it is now), and to leave
the daily superintendence to them entirely. The agricultnral

AND FARMING ERROHS. 411

practices, and also the products, were consequently, and almost
universally, at a very low ebb. The work of Taylor appeared
when these evils had become manifest ; and it was received with a
welcome which in warmth was proportioned to the magnitude of
the evil, and to the exaggeration of the promises of speedy and
effectual remedy which the author made, with entire good faith no
doubt, but which were proved, by results, to be anything but cor*
rect to the great majority of his sanguine followers.

Of course, I was among the most enthusiastic admirers of '^ Ara-
tor;" and not only received as sound and true every opinion and
precept, but even went beyond the author's intention (perhaps),
and applied his rules for tillage to lands of surface and soil alto-
gether different from the level and originally rich sandy soils of the
Rappahannock, where his labours and system had been so success-
ful. However, this error was by no means confined to myself;
for his other disciples fully as much misunderstood the directions,
and misapplied the practices.

It was my main object to enrich my then very poor land;
and, for that, Taylor offered means that seemed to be sure and
speedy. According to his views, it was only necessary to protect
the arable land from all grazing, and thus let the vegetable cover
of the land, when resting, serve as manure — to plough deep, and
in ridges — to convert all the corn-stalks and other offal to manure,
and plough it under, unrotted, for the corn — to put the farm under
clover as fast as manured — and the desired result would be sure.
I hoped at first to be able to manure, say 10 or 12 acres a year very
heavily, with the barn-yard manure, and expected that such ma-
nuring would give a crop of 50 bushels of corn to the acre. The
space, so enriched, when in the succeeding crop of wheat, would
be put under clover — and its acquired productiveness be made
permanent, by the lenient rotation of two crops only taken from
the land in four years. But utter disappointment followed. The
manure was put on the poorest (and naturally poor) land ; and it
produced very little of the expected effect in the first course of
crops, and was scarcely to be perceived on the second. Clover
could not be made to live on land of this kind ; and even on much
better, or where more enriched, it was a very precarious crop, and
which, where the growth was best, was certain to yield the entire
occupancy of the ground to natural weeds after one year. The
general non-grazing of the fields under grass, or rather under
weeds, produced no visible enriching effect, and the ploughing of
hilly land (as mine mostly was) into ridges, caused the most de-
structive washing away qf the soil by heavy rains. These results
were not speedily made manifest ; and before being convinced of
their certainty, I had laboured for four or five years in using these
means of supposed improvement of the soil, but all of which

412 FORMER CONDITION OF LAND.

proved either profitless, entirely useless, or absolutely and in somo
cases greatly injurious. And even after trying to avoid the first
known errors, and using all other supposed means for giving dura-
ble and increasing fertility to my worn and poor fields, at the end
of six years, instead of having already achieved great improve-
ment, I was compelled to confess that no part of my poor land was
more productive than when my labours commenced, and that on
much of it, a ten-fold increase had been made of the previously
large space of galled and gullied hill-sides and slopes.

When more correct opinions had been formed in after-time of the
actual condition and requirements of such poor soils, it seemed an
astonishing delusion, which would have been altogether ludicrous
but for its serious effects, that I should have counted so much on
improving such a soil, and by such means. With the exception
of a small part near the river banks (perhaps one-fifth of the then
cleared and cultivated land), which had been originally of very fine
quality, and, however abused and exhausted, was still good land,
the farm generally consisted of a soil of sandy loam, usually about
three inches deep, and through which a single-horse plough could
easily penetrate and turn up the barren and more sandy yellow
sub-soil. Grazing the fields, when not under tillage, had been the
regular practice ; and under it very little growth was to be seen
except the light and diminutive '' hen's nest grass'' (aristida gra-
cilis), which formed the almost universal cover of the poor fields
of lower Virginia, in the intervals between tillage. Add to these
circumstances of very poor and shallow soil, and barren and sandy
sub-soil, and almost no vegetable cover to turn under, that every
field was more or less hilly, and liable to be washed by heavy rains
— and the judicious reader will see nothing but false confidence
and ignorance displayed in my bold adoption of Taylor's system.
Nor was I convinced of my error until after nearly all the fields
had been successively thrown into ridges by two-horse ploughs, and
all the hilly and more slightly inclined surface had been awfully
washed and gullied, by the exposure of the loose sub-soil to the
action of the streams of rain-water.

While these my supposed measures of improvement were in pro-
gress, I was in habits of frequent and familiar intercourse with my
oldest and best friend, and former guardian, Thomas Cocke, who
resided then on his Aberdeen farm, and since and now, on Tarbay,
adjoining my own land. My friend was a man for whose mind and
mental cultivation I could not but entertain a very high estimation.
But, though all his life a practical and assiduous cultivator, and
finding his greatest pleasure in his farming labours, he yet was a
careless, slovenly, and bad manager, and of course an unprofitable
farmer. Therefore, on this subject, I held in but light esteem the
opinions which he maintained, which were opposed to my own.

Taylor's and davy's doctrines. 413

One of these (and which he had first gathered from some old and
ignorant, but experienced practical cultivators of his neighbour-
hood), was the opinion that our land which was naturally poor
could not " hold manure," to any extent or profit, and therefore
could not be enriched. For years I heard this opinion frequently
expressed by him, and the evident inference therefrom, that the
far greater part of our lands, and of the whole country, was doomed
to hopeless sterility; and as often as heard, I rejected it as a
monstrous agricultural heresy — as treason, indeed, to the authority
of Taylor, and of every other author on agriculture whom I had
read or heard of. But at last I was compelled, most reluctantly,
to concur in this opinion.

What was then to be done ? I could not bear the idea of pur-
suing the general system of the country in continuing to lessen the
already small productiveness of my fields, by their course of culti-
vation. The whole income, and more, was required for the most
economical support of a then small but fast growing family ; and
for any increase of income or net profit, there was no hope, save
in the universal approved resort in all such cases, of emigrating
to the rich western wilderness. And accordingly such became ray
intention, fully considered and decided upon, and which was only
prevented being carried into effect by subsequent occurrences.

Just before this time Davy's " Agricultural Chemistry" had been
first published in this country ; and I read it with delight, notwith-
standing my then total ignorance of chemical science, and even of
chemical names, except as learned by that perusal. There was one
passage of this author which seemed to afford both light and hope
on the point in which disappointment had led me to despair. As
an illustration of defects in the chemical constitution of soils, and
of the remedies which proper investigation might point out, he
adduced the fact of a soil " of good apparent texture," which was
sterile, and seemed incapable of being enriched. The fact which
struck so forcibly on my mind was presented in the following con-
cise passage of Lect. iv. " If on washing [for analyzing] a sterile
soil, it is found to contain the salt of iron, or any acid matter, it
may be ameliorated by the application of quick-lime. A soil of
good apparent texture from Lincolnshire, was put into my hands
by Sir Joseph Banks as remarkable for sterility. On examining
it, I found that it contained sulphate of iron ; and I offered the
obvious remedy of top-dressing with lime, which converts the sul-
phate into a manure."

Much the greater part of my land, and of all the land of lower
Virginia, seemed to me just such as Davy described in this single
and peculiar soil. It was certainly of " good apparent texture,"
that is, it was neither much too clayey or too sandy, nor had it any
other apparent defect to forbid its being fertile in a very high
35*

414 SALTS OF IRON IN SOIL.

degree. Yet it was and always had been sterile, and, as my ex-
perience now concurred with that of my older friend in showing, it
could not be either durably or profitably enriched by putrescent
manures. Could it be possible that the sulphate of iron (copperas)
which Davy found in this soil, and which be evidently spoke pf as
a rare example of peculiar constitution, could exist in nineteen-
twentleths of all the lands of lower Virginia ? This could scarcely
be ; and yet, in despair of finding other causes, I set about search-
ing for this one.

It was not difficult, even for a reader so little instructed in
chemistry, to apply the test for copperas. It was only necessary
to let a specimen of the suspected soil remain soaking in pure
water, until any copperas, if present, would be dissolved ; then to
separate the fluid by pouring off and filtration, and then to add to
the fluid some of the infusion of nut-galls. If copperas had been
held in solution, the mixture would produce a true inh, of which
the smallest proportion would be made visible in the before per-
fectly transparent water. But all these first attempts were fruit-
less, and I was obliged to conclude that the great defect, or impedi-
ment to improvement, in most of our soils, was not the presence
of the salts of iron. But though not a salt^ of which one of the
component parts was an acid, might not the poisonous quality be a
pure or iincomhined acid ? This question was raised in my mind,
and the readiness produced to suppose the affirmative to be true, by
several circumstances. These were, 1st. That certain plants known
to contain acid, as sheep-sorrel and pine, preferred these soils, and
indeed were almost confined to them, and grew there with luxuri-
ance and vigour proportioned to the unfitness of the land for pro-
ducing cultivated crops. 2d. That of all the soils supposed to be
acid which I examined by chemical tests, not one contained any
calcareous earth.* 3d. That the small proportion of my land, and
of all within the range of my observation, which was shell?/, and of
course calcareous, was entirely free from pine and sorrel, and more-
over was as remarkable for great and lasting fertility, as the lands
supposed to be acid for the reverse qualities. Shells, or lime,
would necessarily combine with, and destroy, all the previous pro-
perties of any acid placed in contact; and therefore, if acid were
present universally, and acting as a poison to cultivated plants, it
seemed plain enough why the shelly lands were free from this bad

* I was not tlien aware of the important and novel fact which I after-
wards ascertained and established, and which is now fully received (with
very slight acknowledgment of its source) by the geologists of this country,
tha.t a.l77iost all the soils on the Atlantic slope of this country, and even including
nearly all limestone soils, are also entirely destitute of carbonate of lime,
though that ingredient seems nearly if not quite universal in all the best
soils of England and the continent of Europe.

SUPPOSITION or ACID IN SOIL. 415

quality, and by its absence had been permitted to grow ricb, and to
continue productive. Every new observation served to add strength
to this notion ; and in our tide-water region generally, and even iu
my own neighbourhood, there were plenty of subjects for observa-
tion and comparison, both in small shelly and fertile spots, and a
vast extent of poor pine and sorrel-producing lands. Still, I could
obtain no direct evidence of the presence of acid, either free or
combined, by applying chemical tests to soils (as was tried in many
cases), nor was there any authority in my oracle, Davy's " Agri-
cultural Chemistry,'^ nor in any other work which I had read, for
supposing vegetable acid to be present in any soil. Though Davy
adds to the supposition of the presence of the "salt of iron,'' "or
any acid matter," it is clear from the whole context that he had in
view the possible and extremely rare presence of a mineral acid (as
the sulphuric), and not vegetable acid, which my views required,
and my proofs were afterwards brought to maintain. Sulphuric
acid is sometimes found in certain clays, and in combination with
iron is also in peat soils ; but these facts have no application to
ordinary soils of any country. Of course, this absence of authority
would, to most inquirers, have seemed fatal to the position of an
acid principle being generally present in the soils of Virginia, and
in great quantity and power of injurious action. This was, indeed, a
great obstacle opposed to the establishment of my newly formed
opinion ; but it was not yielded to as insuperable. Diffident as I
then was of any such views of my own, and holding the dicta of
Davy as the highest authority, and even his omission of any posi-
tion as evidence that it was untrue, or unknown, still I was not
daunted, and supposed it possible that the soils of this country
might vary essentially in composition, in this respect, from those
of England; or barely possible that even the great chemical philo-
sopher might not have observed the presence of vegetable acid in
the comparatively few cases of its existence in English soils. The
later observations of subsequent years added much to my evidences
of the existence of acid in soils ) and still later and scientific inves-
tigations of chemists have served to establish that there is an acid
principle in most soils, in the humic or geic acid. But these dis-
coveries of chemists had not been published in 1817 (if indeed
known to any), nor had my own observations reached to all the
proofs which I afterwards (in 1832) published in the first edition
(in book form) of the " Essay on Calcareous Manures," and which
were still in advance of the publication of the now generally re-
ceived opinions of the geic or humic acid. It must therefore be
confessed, that if I reached a correct conclusion, it was not on suf-
ficiently established premises, and known chemical facts. However,
reached it was, whether by right or by wrong reasoning ; and how-
ever little supported by direct proof or authority, I was almost sure,

4]$ , FIRST EFFORT TO MARL.

in advance of any known experiment, first, that the cause of the
unproductiveness and unfitness for being enriched of most of our
lands, was the presence of acid — and secondly, and consequently,
that the application of lime, or calcareous earth, would, by taking
up and destroying the poisonous principle, leave the soil free to re-
ceive and to profit by enriching manures.

• But even if this theoretical position had been demonstrated, still
it might furnish no jprojitahle practical remedy. For, admitting
that the application of calcareous matters would relieve the soil of
its great evil, and make it capable of receiving subsequent improve-
ment, yet after being so relieved, the land, I supposed, would be
still as poor as before, and would require all the manure, labour,
and time, necessary to enrich any very poor soil; and these might
be so expensive, that the improvement of the land would cost more
than it would afterwards be worth. These considerations served
to lessen my estimation of the practical utility of the theoretical
truth, and to make my earliest applications of the theory to practice
hesitating, and very limited in extent.

Having settled that calcareous matter was the medicine to be
applied to the diseased or ill constituted soil, I was luckily at no
loss to find the materials. In some of the many ravines which
passed through my land, and on sundry parts of the river bank,
were exposed some portions of the beds of fossil shells which un-
derlie nearly all the eastern parts of Virginia and several other
southern states ; the deposit which then had obtained in this region,
though improperly, and still retains the name of marl. I began
operations in February, 1818, at one of the spots most accessible
to a cart. The overlying earth was thrown off, and a few feet in
width of the marl exposed, in which a pit was sunk to the depth
of but three or four feet. When night stopped the very slow dig-
ging and throwing out of the marl, the slowly oozing water filled
the pit ; and as no proper plan of draining had been adopted, the
first shallow pit was abandoned, and another opened. In this labo-
rious and wasteful manner there was as much marl obtained as I
was then willing to apply. It served to give a covering of 125 to
200 bushels per acre, to 2^ acres of new ground. The wood on
the land had been cut down three years before, and suffered to lie
and rot until cleared up for cultivation in 1818. Though poor
ridge land, and of what I deemed of the most acid class of soils,
still the previous treatment had given to it so much decompose(i
vegetable matter, that its product would necessarily be made the
best which such a soil was capable of bringing! And because of
the superabundance of food for plants then ready to act, this was
not a good subject to show the earliest and greatest benefit of neu-
tralizing the acid. However, notwithstanding this circumstance,
and the small amount and poverty of the marl (which contained

FIRST RESULTS OP MARLING. 417

but one-third of calcareous matter), the improvement produced was
greater and more speedy in showing than I had dared to hope for.
When the plants were but a few inches high, and before I had ex-
pected to see the slightest improvement (indeed none had been
expected to show in the iBrst year), the superiority of the marled
corn was manifest, and which continued to increase as the growth
advanced. My high gratification can only be appreciated by a
schemer and projector; but such a one can well imagine my feel-
ings and sympathize in my triumph. The increase of the first
crop, corn, I stated by guess, in reporting the experiment, to be
fully 40 per cent., and that of the wheat which sticceeded was
much greater. Later measurements of other products of experi-
ments have induced me tcf believe that I had underrated the
amount of increase in this first application. [This experiment is
the first stated, and at length, at page 117 of " Essay on Calcareous
Manures," 5th edition. Throughout this republished article, the
references to the pages of the ''Essay on Calcareous Manures,"
will be changed from the previous to the present edition.]

Grreat as had been the labour of this application, and small as
its increased product (comparing both with later operations), the
results served completely to sustain my theoretical views, and also
showed the remedy for the general evil to be far more quick, and
more profitable, than I had counted on. Another person would
probably have despised this small increase to the acre, if supposing
the effect to be but temporary ; and this all would have inferred,
whether judging by comparison with all other manures known in
practice, or even if by the authority of books. For the best in-
formed of the old writers (even Lord Kames, for example), while
claiming for the effects of marl great durability, still consider that
at some period, say twenty or a hundred years, the effects are to
cease. But my views were not limited within any practical expe-
rience, or authority, but by my own theory of the action ; and
that theory taught me to infer that the benefit gained would never
be lost, and that under proper cultivation, the increase of product
would still more increase, instead of being lessened in the course
of time. In thus fully confiding in the permanency of the im-
provement, I was at once convinced of the operation being both
cheap and profitable. All doubt and hesitation were thrown aside,
and I determined to increase my labours in marling to the utmost
extent of my views. Still the want of spare labour, and the esta-
blished routine of farm operations which occupied all the force,
retarded my operations so much, that no more than twelve more
acres (for the next year's crop) were marled in that year (1818).

It forms an essential part of the character of an enthusiastic and
successful projector, and especially an agricultural projector, to be
as anxious to inform others as to profit himself. Of course I tried

4J8 EARLIEST OPINIONS OF SOILS.

to bestow upon and share my lights with all my neighlbourS and
other farmers whom my then humble position and secluded life
permitted me to meet. This disposition also caused my earliest
attempt at writing for even so small a portion of the public as con-
stituted a little agricultural society of which I had induced the
establishment in my neighbourhood. To show my earliest opinions
and statements on this subject, I will here quote the material part
of a communication made to that society, and which was written
in October of the year of my first experiment in 1818. I copy
the extract just as it then stood, and with all its defects of form
and of substance. I then shrunk in fear from the greater publicity
which the press would have afforded} and had not the remotest
anticipation that my first effort, then made, would lead me to the
extended intercourse since established and maintained with the
public, both by writing and printing.

* * * * " We should be induced to infer from the remarks of
those writers who have treated on the improvement of land, that a
soil artificially enriched is equally valuable with one which would
produce the same amount of crop from its natural fertility ; and
that a soil originally good, but impoverished by injudicious cultiva-
tion, is no better than if it never had been rich. If this conclusion
be just (and the contrary has not been even hinted by them), it is
in direct contradiction to the opinion of many intelligent practical
farmers, with whom my own observations concur, in pronouncing
that soils naturally rich (although completely worn out), will sooner
recover by rest — can be enriched with less manure — and will longer
resist the effects of the severest course of cropping, than soils of as
good apparent texture and constitution, and in similar situations,
but poor before they were brought into cultivation. Should the
latter opinion be correct, it is of the utmost importance that the
subject should be investigated; as the only conclusion that can be
drawn from it is, that such land must have some secret defect in its
constitution, some principle adverse to improvement ; and until this
is discovered and corrected, it is an almost hopeless undertaking to
make a barren country permanently fertile, by means of animal and
vegetable manure.

^' That e7iclosing^ has but little effect in improving land naturally
barren, is sufficiently proved by poor wood-land. This has had the
benefit of enclosing for perhaps thousands of years, and is yet
miserably poor. It may be said that leaves are not to be compared
in value to grass or weeds ; but surely leaves ought to improve as
much in a thousand years, as grass or weeds in twenty. Besides,
it is well known, that leaves taken from this very land, and applied
elsewhere, have produced much benefit; and the advocates of en-

* The non-grazing system, or manuring land by its own growth.

EARLIEST OPINIONS OF SOILS. 419

closing must agree with me in ascribing to this cause the natural
fertility of the most valuable [wood] land.

^'As to manuring, there are but few farmers who have not, like
me, experienced complete disappointment in endeavouring to im-
prove land so little favoured by nature. In the usual method of
summer manuring, by movable cow-pens, the most negligent far-
mers give the heaviest covering, by suffering their pens to remain
stationary sometimes six or eight weeks. I have known the surface
in this manner to be covered an inch thick with the richest of ma-
nures, and yet, after going through the same course of crops and
grazing with the adjoining unmanured land for six years^ it could
not be distinguished. * * * * * * si*

^' If any one principle should be always found in one kind of
soil, and as invariably absent in the other, we might reasonably infer
that that was the cause of fertility or barrenness. Judging from
my very limited observations, it appears evident that calcareous
earth constitutes a part of every soil rich in its natural state, and
that whenever a soil is entirely or nearly deficient, it never can be-
come rich of itself, and if made so by heavy doses of dung, will
soon relapse into its former sterility.

" Let us observe how facts coincide with this opinion. The lower
part of Virginia is generally poor ; narrow stripes along the rivers
and smaller watercourses are nearly all the high lands that are
valuable, and in this class, exclusively, shells are seen so frequently,
and in such abundance, that it seems highly probable that they are
universally present, but so finely divided as not to be visible.
When we know the change produced by calcareous earth in the
colour and texture of soil, and in a field of an hundred acres, all of
the same dark-coloured mellow soil, shells may be seen in only a
few detached spots, we cannot but attribute the same effects to'
the same cause, and allow calcareous matter to be present in every
part.

" The durable fertility of land which contains shells in abundance
is so wonderful, that I should not dare to describe it, were not the
facts supported by the best authority. The calcareous matter for
ages has been collecting and fixing in the soil such an immense
supply of vegetable matter, that near two centuries of almost con-
tinual exhaustion have not materially injured its value. I have
seen fields on York, Jame^, and Nansemond rivers, now extremely
productive, which are said to have been under cultivation for thirty
and forty years, without any aid worthy mentioning, from rest or
manure.

*' The same cause operates on low lands, formed by alluvion, and
situated on streams accustomed to overflow. Such land is, with
very few exceptions, of the first quality ; and it is made so by the
calcareous matter which the currents must necessarily convey from

420 EARLIEST OPINIONS OP SOILS.

the strata of marl through which they pass; and which being in-
timately mixed with sand, clay, and vegetable matter, is sufficient
to form the finest and deepest soil. All the rich low grounds
which I have had an opportunity of observing, have marl on some
of tho streams which fall into them, and I have not heard of any
on those few which are poor. Not a solitary instance of shells
being found in poor land of any description has come to my
knowledge.

" If these premises are correct, no other conclusion can be drawn
from them but that a proportion of calcareous earth gives to soil a
capacity for improvement which it has not without ; and it also
follows, that by an application of shell marl, the worst land would
be enabled to digest and retain that food, which has hitherto been
of little or no advantage. * * * >}; sk *

^' The property of fixing manures is not more important in marl,
than that of destroying acids. The unproductiveness of our lauds
arises not so much from the absence of food as the presence of
poison. We are so much accustomed to see a luxuriant and rapid
growth of pines cover land on which no crop can thrive, that we
cannot readily see the impropriety of calling such a soil absolutely
barren.

" From the circumstance of this soil being so congenial to the
growth of pine and sorrel (both of which are acid plants), it seems
probable that it abounds in acidity, or acid combinations, which
(although destructive to all valuable crops) are their food while
living, and product when dead. The most common forest trees are
furnishing the earth with poison as liberally as food, while it depends
entirely on the presence of the antidote, whether one or the other
lakes eifect. I have observed a very luxuriant growth of sorrel on
land too poor to support vegetables of any kind, from green pine
brush having been buried to stop gullies ; and it is well known how
much land on which pines have rotted is infested with this perni-
cious plant. Marl will immediately neutralize the acid, and this
noxious principle being removed, the land will then for the first
time yield according to its actual capacity. Sorrel will no longer
be troublesome; arid, by a very heavy covering, I have known a
spot rendered incapable of producing it, although the adjoining
land was thickly set to the edge. Pines do not thrive on shelly
land, whether fertile or exhausted. To this cause I attribute the
great and immediate benefit I derived from marl on new ground.
The acid produced by the pine leaves is destroyed, and the soil is
capable of supporting much heavier crops, without being (as yet)
at all richer than it was.'' *******
— Communication to Prince George Agricultural Societi/, 1818.

Before proceeding to state later experiments, and general prac-

MISTAKEN IDEAS OF MARL. 421

ticc and results, it will be necessary to recur to some other con-
nected branches of the subject. The reader will pardon the apparent
digression.

So well established and general has the opinion now become that
this marl is a manure, and a most valuable one, that it may seem
strange that I should have only arrived at such an opinion indirectly,
by the train of reasoning indicated above. There were hundreds of
persons who afterwards said, " Oh ! / never doubted that marl was
a good manure ;'^ but not one of whom had been induced before me
to try its operation. But passing by these postponing believers,
and 'all others who confessedly never attached any value to this
great deposit, it may require explanation why I had not learned its
value from English works which treat so extensively on marl, even
though I had then had access to but few of them. It was precisely
because I had read attentively some of the English accounts of
marl that I was deterred from using our marl, which agreed with
it (apparently) in nothing but name. Struck with the importance
attached to marl in England, I had earnestly desired to find it, and
had searched for it in vain, years before the early beginning of my
farming. The name induced a close examination of what was
called marl here; but the "soapy feel," the absence of grit, the
crumbling and melting of lumps in water, &c., which were the most
distinguishing characteristics of the marl of the English writers,
were in vain looked for in our shell beds — of which the earth was
generally sandy, never " soapy," and of which the lumps were often
of almost stony hardness, and if not, at least showed nothing of the
melting disposition of the English marls. I had before this found,
however, in the American edition of the " Edinburgh Encyclopae-
dia," more modern and correct views of marl, and had thereby
learned to prize calcareous matter in general as an ingredient of
soil, whether natural or artificial. But even admitting that the
shelly portion of our marl would slowly decompose, and gradually
furnish some manure to the soil, still it seemed that there was little
prospect of its operating as the English marl, of such very different
texture and qualities. I then supposed that the shells which had
resisted decomposition, even where exposed on the surface of the
beds, for centuries, would be as slow to dissolve, and to act as ma-
nure, if laid upon the fields. Still, notwithstanding these grounds
of objection, the general idea of the value of calcareous manures
would have induced me earlier to try fossil shells, but for being
deterred therefrom by the only actual facts then known of the use.
When speaking of my thought of trying marl to my friend Mr,
Thomas Cocke, he told me that it was not worth the trouble ; that
he (attracted merely by the name of "marl"), had made several
small applications, in 1803, on soils of different kinds, and that he
had found almost no visible benefit ; and he had attached so little
36

422

importance to tlie trial, that he had never thought to mention it to
me, until induced by my remark. This communication was enough
to check my then slight disposition to try marl. The old experi-
ments of Mr. Cocke, as well as some much older, heard of after-
wards, and, like his, considered worthless by the makers and almost
forgotten, are stated at page 115 of this edition of the ''Essay on
Calcareous Manures.''

As soon as I was satisfied that I had found in marl a remedy for
the general and fixed disease of our poor lands, it became very
desirable to know the strength of different beds, and of the difi'ercnt
parts of the same bed. The rules of Davy for determining the pro-
portion of carbonate of lime were easy to apply ; and having pro-
vided myself with the necessary tests and other means, I was soon
enabled to analyze the specimens with ease and accuracy- This
was a delightful and profitable direction of my very small amount
of chemical acquirements, and served to stimulate to further study.
The amount of my knowledge was indeed very small — and is still
so, with all later acquirements added. But little as I had been
enabled to learn of chemistry, the possession led me to adopt my
views of the constitution of soils, and enabled me to double the
product, and to much more than double the clear profit and pecu-
niary value of my land, in the course of a few years thereafter.

Though my own doubts as to the propriety and profit of marling
had been removed by my first experiments, it was not so with my
neighbours. Induced by my example, small applications were in-
deed made by two of them only, in the next year after my first trial.
But either because the land had been kept too much exhausted of
its vegetable matter by grazing as well as by cropping, or because
the experimenters could not think of the operation of the manure
as different from that of dung, or stable manure, or for both these
reasons, it is certain that they were not encouraged by the results
to persevere. They stopped marling with their first trial, until
several years after, when both recommenced, then fully convinced
of the benefit by my results, and were afterwards among the largest
and most successful early marlers. One of these persons was the
late Edward Marks, of Old Town, and the other my old friend
Thomas Cocke — who, though he had led me to find out the disease,
could not himself be speedily convinced of its true nature, or of the
value of the remedy. As late indeed as 1822, when he walked
with me to an enormous excavation which I was then making in
uncovering and carrying out marl, he said to me, " In future time,
if marling shall then have been abandoned as unprofitable, this
place will probably be known by the name of ^Ruffin's Folly.'"
For some years, my marling was a subject for ridicule with some
of my neighbours; and this was renewed, when in after-time tho

FIRST EFFECTS AS EXAMPLE. 423

great damage caused by improper applications began to be seen, and
which will be described in due order.

Having had in view from the beginning the true action of marl,
and fully believing that its good effects would be permanent, and
even increasing with time under a proper system of tillage, I was
no more discouraged by what some deemed small profits, than I
was annoyed by the incredulity and ridicule of other persons. Al-
most all the farms in the neighbourhood, except mine, were re-
gularly and closely grazed when not under a crop, and of course
they had not stored up in the soil much either of inert vegetable
matter, or its acid product. Mine had not been grazed since 1814,
and had been rested two years in every four ; and the poorest land
three years in faur. And though, in truth, no increased production
had been obtained by this lenient treatment, inasmuch as the in-
crease of acid counterbalanced the increase of vegetable food, still,
when marl was applied, the acid was immediately destroyed, and
the f^od left free to act. The effect of marling was generally shown
most plainly on the first crop of corn, and the limits could be easily
traced by the deep green colour of the plants before they were five
inches high ; and the increased product of the first crop on acid
soils rarely fell under 50 per cent., was most generally 100, and
has been known to be 200 per cent. But even such increase was
not satisfactory to many persons, until the action of marl came to
be better understood, and the permanency of the effects was credited.
In five or six years after my commencement, there were few if any
of those of my neighbours, who had marl visible on their lands,
who had not begun to apply it. And though it has been injudi-
ciously as well as insufiiciently applied since, and not one-fourth
of the full benefit obtained, still the general improvement and in-
creased products of the marl farms of Prince George have been
very great. The existence of marl, too, which was known at first
but on a few ftirms in my own neighbourhood, has been since dis-
covered in many other and remote parts of the county ; and wher-
ever accessible it is valued and used. The like observations will now
apply to most of the other counties of lower Virginia. Wherever
the effects of marling could be seen for a few years, the early in-
credulity not only disappeared, but most persons were even too
ready to believe in marl's possessing virtues to which it has no claim.
Thus, ignorant or careless of its true mode of operation, they crop
the marled lands more severely than before ; and if they are not
thereby soon reduced as low as their former state of sterility, they
are made to approach it as nearly as possible, and at a sacrifice of
nine-tenths of the profit from marling which a more lenient and
judicious system of cultivation would have insured.

In 1819, the second year of my operations, my marling was in-
creased to 62 acres, but most of it at much too thin a rate. la

424 CONTINUED MAULING LABOL'Rrf.

1820, only 25 acres were covered, tliough at 600 bushels or even more
to the acre. Up to this time I had done as most other persons have,
that is, attempted to marl " at leisure times," and without making
it a regular employment for a certain additional force, or reducing
the amount of cultivation, or of other operations on the farm. No
person will ever marl to much advantage who does not avoid this
error; and this year's labours showed the necessity of an alteration.
The next year, two horses and carts, with the necessary drivers and
pit-men, were appropriated to marling at all times when weather
permitted, except during harvest, thrashing, and wheat-sowing
times. Viewing marling too as the most profitable operation, ex-
cept the saving of a crop already made, it was made a fixed rule of
the farm that marling was to be interrupted for nothing else. My
corn shift for that year was reduced in size one-half — so that one-
half could be marled while the other was under cultivation. By
these means, I marled 80 acres this year, 1821 (and that much too
heavily), and had all the lessened corn-field on marled land. "The
product of the half was equal to .what the whole had brought before,
and I was enabled thereafter to have every field marled over in
advance of its next cultivation. In 1822, the land marled was 93
acres, 100 in 1823, and 80 in 1824, which served to cover nearly
all of the then cleared land requiring marling. The next three
years' marling amounted respectively to 50 acres, 24 acres, and 27
acres, being principally upon land subsequently cleared and brought
into cultivation. Since then, there has been no marling on the
farm, except on wood-land, not yet cleared, and on small spots for-
merly omitted, and of which no account was taken. With the
exception of such spots (and some such still remain, because of their
inconvenient position), all the land which was not naturally calca-
reous, or too wet, or too steep for carting on, had been marled by
1827 J and none has required any additional dose, though some of
the thinnest covered places had been re-marled long before that time,
so as to bring them to a proper constitution. (1842.)

In 1824, I first observed (and had never before suspected such
efi"ect), the injury caused by having marled acid soil too heavily.
To show my first impressions, I will copy the words of my farm
journal, written on the very day on which the discovery was fully
made.

''June 13th, 1824. Observed a new and alarming disease in a
large proportion of ray corn ; and, what makes the matter much
worse, the evil is certainly caused by marling. The disease seems
to have commenced when the corn was from 6 to 10 inches high,
and to have stopped its growth. Its general colour is a pale sickly
green, and the leaves appear so thin as to be almost transparent :
next, they become streaked with rusty red, and then begin to die at
the upper ends. Several pulled up, showed no defect, or injury

DAMAGE TO CROPS BY MARLINO. 425

from insects, among tlie roots. All the land marled from pits Nos.
7 and 9 (both yellow) from 1820 to 1822, is so much diseased as
to promise not more than half a crop. The corn is twice as large
as on the spaces left for experiment without marl, yet looks much
worse ; though three weeks ago its superiority in colour and vigour
was even more than in size. With but few exceptions, the land
newhy marled from the same pits, and the old marling from Nos. 1
and 8 (both blue), as well as that not marled, are free from this
disease. The parts most affected are those which were driest and
poorest, and of course were least covered with vegetable matter.
Yet though the corn on this old marling is generally so bad, it is
yet evident that the land is more benefited by the manure than at
first. Flourishing stalks of corn, 18 to 24 inches high, are seen fre-
quently within a few feet of those most hurt by this disease."

Subsequently, when the whole extent of injury could be seen,
the following remarks were written iu' the journal, at the date
below.

^' October 15th. The damage caused by marl to this crop I sup-
pose to be about one-third of what the land would otherwise have
made, judging from the present and former measurements of the
same laud, where experiments were made.

" Nearly all the heavy marling in Finnies (at 800 bushels), about
20 acres,* suffered by it; the poorest and lightest most injured,
here and in Court-House field. The few rich spots escaped, as did
most of the piece plastered (on the heavy marling) in 1820. The
marks of this experiment were destroyed, and the superiority was
not so regular as to enable me to trace the outlines of the gypseous
earth — ^but an acre of corn might be taken which certainly was
plastered, better than any other acre in the old land. This at least
proves that gypsum contained [if any] in the marl has not caused
the disease. The poor land, lightly marled in 1819, showed but
little of the disease, and none was found in the piece not marled,
nor in any marled since the last crop [or now first cultivated since
being marled.]

''In Court-House field the injury was confined to 19 acres, the
poorest part of the field, which was in corn in 1821,"|" marled and
fallowed 1822, and in wheat 1823, corn 1824. The remainder of
the old land, which had not been cropped so severely, and was
covered as heavily with blue marl, brought a fine crop, quite free
from the disease. The new ground was mostly marled very heavy
(800 bushels of 45 per cent.),I and this and all my former clear-
ings (some marled equally heavy) were also quite free. These

* See Exp. 10, p. 132, Essay on Cal. Man.

f Exp. 11, p. 135.

JExp. 1 to 4,:pp. 117to 121.

36*

426 DAMAGE TO CROPS BY MARLING.

facts satisfy me that it was not the quality, but the over quantity
of marl which has caused the evil; and that the land which has
escaped, owes its safety to its containing more vegetable matter.
I forgot to state that on some of the lightest spots of South field the
wheat was much injured, though blue marl was used there.

" If I had followed my own advice to others, ' to put no more
marl at first than would but little more than neutralize the soil, and
repeat the dressing afterwards,' this evil would not have fallen on
me. The present loss is not much ; but it makes me expect the
same on all similar land, marled as heavily. I -shall endeavour to
avoid it, by giving vegetable matter to the soil; either by manur-
ing, or iDy allowing one or two more years of grass in the fii-st term
of the rotation. Why the quantity of marl applied should do harm
in any case, is more than I can tell ; but I draw this consolation
from the discovery — if a certain quantity (say 500 bushels per
acre) is too much for present use of the soil, it proves that it will
combine with mo^e vegetable matter, and fix more fertility in the
soil, than I had supposed. That the second crop should be injured,
and not the first, is owing to the unbroken state of the shells at
first, and, by their being reduced, twice as much calcareous matter
is in action after a few years.''

Thus it will be seen, from these entries made at the time, that I
took a correct view of this great and unlooked-for evil, and was by
no means discouraged, or induced to lessen my efi'orts in marling.
Bat in all later operations on poor land, the quantity was lessened
from 500 and 600 bushels (and even more of the poorest marl), to
about 300 bushels. With this alteration, the operation was con-
tinued with as much zeal as before; and also at a later time on an-
other farm (Shellbanks) purchased afterwards, and where I marled
upwards of 400 acres.

When this injury was first discovered, about 250 acres of very
similar land had been marled so heavily that the like mischief was
to be looked for in the next crop, and thenceforward, if not guarded
against. For a more full account of this disease, and my opinions
thereon, I must refer to what has been before published.* It is
sufficient here to say that by pursuing the means there advised — in
allowing more rest from grain crops, furnishing vegetable matter
to the land, in its natural cover of weeds, in clover, and in farm-yard
manure so far as the limited supply sufficed — that no very great
loss was subsequently suffered, except in the field where the disease
was first discovered, and which was marled in 1819. This field
was too remote and inconveniently situated, to be manured from
the barn-yard; and from that and other causes (including the
failure of the first seeding of clover), that field only still shows in-

* Essay on Calcareous Manures, ante, 155.

REPORT TO BOARD OF AGRICULTURE. 427

jury from marling in the present crop (1839); so much diminished,
however, that its general average product this year [1842] is
fully twice as much as the land could have brought before being
marled.

NOTE y.

DESCRIPTION AND ACCOUNT* OF THE DIFFERENT KINDS OF MARL,
AND OF THE GYPSEOUS EARTH, OF THE TIDE-WATER REGION OF
VIRGINIA.

Report to the State Board of Agriculture, hy Edmund Ryffuij

Member and Corresponding Secretary of the Board, made in

1842, and now corrected^ altered^ and enlarged.

Within the last twenty-five years there have been produced from
the application of calcareous manures more improvement and bene-
fit, both agricultural and general, in lower Virginia, than from
all other means and sources, numerous and valuable as have been
the agricultural improvements made. And for the latter half of
that time, no one agricultural subject has been treated of more at
length in the publications of this state. Still, there is much re-
quired to be known ; and it has very often, and not less so recently
than formerly, been required of the writer, who has furnished to
the press the larger part of all that has thence proceeded on this
subject, to give answers to inquiries, which, however variously
worded, amounted in substance to the question, " What is marl V
— or " Is my marl (or whatever earth was so termed) good marl,
and likely to be profitable as manure ?" It has therefore appeared
to the writer that it would be useful to prepare something like a
natural history, or general and full description of the marls of low-
er A^'irginia ; and also of the kindred and yet very different mineral
manure, the gypseous earth, or ''green-sand'^ earth, concerning
which latter so much error and delusion have been spread and long
maintained, and so little of truth or useful information derived from
the scientific sources generally respected as the highest authority.

The main difficulty in the treating of this subject is presented in
the outset in the very term '' marl,'' which is altogether misapplied
now in this country, though not so much as it has been, and per-
haps still is in England. Since this general course of misapplica-
tion was set forth by the writer at length in the '' Essay on Calca-
reous Manures," there have become general in this country still
other misapplications of this always misapplied term. Eoi* the
" green-sand" earth of New Jersey, which before had been called

428 CHARACTER OF TRUE MARL.

'^ marl" by illiterate farmers only, has been since received under
that name by chemists and the scientific reporters of geological sur-
veys ; and thus confusion has become still " worse confounded."
In the following pages, I shall be compelled, as heretofore^ to yield
in part to such misapplication of the term ; but at the expense of
some otherwise useless repetition, and frequent explanation, shall
hope to avoid misleading readers as to each of the particular earths
under consideration. And I shall in no case apply the term marl
to any but a calcareous earth, or mixture of earths, and of which the
calcareous ingredient or proportion of carbonate of lime is deemed
sufficient to constitute the most important, if not indeed forming the
only important or appreciable agent of fertilization ; and therefore
I shall not so designate either the fine clays (not calcareous, or very
slightly so), and formerly, if not now, called marl, in England, or
the green-sand earths of New Jersey, Delaware or Virginia, when
containing very little or no carbonate of lime.

True marl, as correctly understood by mineralogists, is a fine
calcareous clay, containing very little silicious sand, and none coarse
or separate ) of firm texture — not plastic, or very adhesive ; does
not bend under pressure, but breaks easily, and after being dried,
the lumps speedily crumble when immersed in water. It is man-
ifest, from its laminated appearance and fracture, that this true marl
had been originally suspended in rapidly flowing waters, and de-
posited at the bottom by subsidence, when the waters became com-
paratively still ; as when a rapid river, turbid with calcareous clay,
reached a lake. Thus, from its manner of formation, such marl,
however argillaceous, was of a texture very different from the almost
pure or the most tenacious clays. The carbonate of lime also tends
to preserve an open and mellow texture in true marls, disposing the
lumps readily to yield and crumble, or fall to powder or to thin
flakes, under atmospherical influences, which would only affect clay
by making it an intractable'- sticky mortar when wet, or lumps of
almost stony hardness when dry. Moreover, there seems good
reason to believe that in true marl there, is a chemical combination
(and not merely a mixture) of the argillaceous and calcareous in-
gredients, induced by their suspension in water, when the particles
of both were in the finest possible state of division, and most inti-
mate intermixture, while so suspended. Besides the crumbling
quality just stated, so different from clay, there is a still stronger
reason for believing that the calcareous and the silicious parts of
true marl are chemically combined, which is, as I have found, that
they cannot be separated by mechanical means, such as agitation
and subsidence in water.* For the suggestion that the different

*The silex and alumina which compose the purest clay, are chemically
combined in the proportions of nearly 65 parts of silex to 36 of alumina j

MARL AND SHELLS OP FRANCE. 429

eartliy parts of true marl are in a state of chemical combination
with each other, I am indebted to the " Essaisur la 3Iarne," of M.
Puvis, which work, in an abridged form, I translated and published
in the third volume of the Farmers' Register. The author there
also states that the marls of France are principally, if not always,
of fresh-water formation, as is shown by the shells they contain be-
ing either such as belong to rivers and lakes, or to the land. This
is different from anything known in lower Virginia; all our known
marls, whether properly or improperly so termed, being deposits
made in a former sea, and the shells being those of sea-animals.*
But though it is proper to describe that which only is truly
" marl," before speaking of what is improperly so called, it is also
true that there is nothing to tell of the use of any true marl in
Virginia, and scarcely of its existence in the tide-water region. —
I have as yet seen it in but few places, and there in thin layers
only, and then overlying ordinary beds of fossil shells, and inter-
mixed therewith.

and with this, to constitute true marl, carbonate of lime is also combined,
forming a triple earthy compound, or perhaps a quadruple compound, if
including the small proportion of oxide of iron, which is a general or uni-
versal constituent part of all clays.

* " It may be of some interest to scientific investigators to know more
particularly the shells of these marls of France. In a catalogue annexed
to the original ^ Essai sur la Marne,' the author names the following shells :

In a marl sent from St. Trivier — yellowish, compact, of homogeneous ap-
pearance, and coming to pieces finely and easily in water —
Land shell — Turbo elcgans.
Eiver shells — Helix fascicularis. Helix vivipara, fHelix teutacula, f Mya Pic-

torum.

In a marl from Cuiseaux, Saone et Loire —
Eiver shell — Melanopside (of Lamarck.)

In a marl from Leugny, in Yonne —
La?id shell — f Chassilie ridee (of Lamarck, and Draparnaud, f Helix lubrica.

In a marl from St. Priest in Dauphiny — earthy, yellowish, very easy to
crumble in water —
Land shell — f Ambrette alongee, of Lamarck and Draparnaud, f Helix hispida.

In an analogous formation of marl, in the basin of the Rhone, between
Meximieux and Montluel, the Helix striee, a land species, is found in great
abundance."

M. Puvis states that among these, and among all the species of shells
found in the marls of the basin of the three great rivers, Saone, Rhone,
and Yonne, there are no remains of sea shells. All seem to have been
formed under fresh Avater. "But (he continues) as these marls contain
land shells, often in great abundance, we must conclude, that the revolution
which heaped up the marls, has been preceded by a time in which the land
was not covered by water, in which the earth producing vegetables, per-
mitted the multiplication of the species of land shells which were found in
these marls." — Essai sur la 3farne, p. 8 to p. 24, and translation in Farmers'
Register, iii., note to p. G92.

f Living species are still found in the same region similar to those marked
thus.

430 FORMATION OP TRUE MARL.

This marl was thus found in two of my diggings, one on Coggins
Point farm, and the other at Shellbanks, in Prince George county.
In both cases, though perfectly characterized, the quantity of true
marl was too small to be used separately from the more calcareous
and much thicker stratum of shell marl below. This true marl was
in many horizontal layers, few of which were severally more than an
inch in thickness, separated by other layers, sometimes very thin,
of almost pure shells, broken very small, with some only of the
very smallest entire. The pure argillaceous marl is blue (though
sometimes of buff colour), firm and compact, breaks easily, but does
not bend however moist, and is cut smooth by a knife, leaving a
surface like that of hard soap. This marl contained, in the argilla-
ceous part, free from the shelly parts, only 10 per cent, of calca-
reous matter. Several other specimens, from other localities in the
same region, were about the same strength. Therefore, even if
more plenty, there would seem to be no inducement to use our true
marl where the beds of fossil shells, called marl, and usually so
much richer in calcareous matter, can be drawn from. But in Eu-
rope, clay marl is reported as rich as 40 to 60 per cent, of calca-
reous matter, and indeed richer, gradually running into lime-stone
or impure chalk.*

But though it is proper to know, and to bear in mind, what is
understood by the term marl, by mineralogists, and by the best in-
formed English and French agricultural writers, in regard to the
extensive marlings in those countries, yet it is necessary in Yirgi-
nia to conform generally to the usage which gives the name of marl
to all earths largely mixed with fossil shells, or their fragments j
and as the term is so far improperly extended, I would carry it still
farther, and make it embrace all natural calcareous earths not of
stony hardness. This arrangement then would indeed include true
marl, but merely as one class, and that one the least noticeable for
abundance or value of all in this country. The following scheme
of classification will conform to this view, and serve to make more
clear the descriptions that will follow : —

*Such cases as are named above can scarcely be deemed exceptions to
the entire non-existence of true marl in this region. These limited de-
posits were doubtless formed by the abrading, stirring up, and suspension
of the upper part of the beds of shelly earth, by some strong current or
agitation of the sea, and the subsequent deposition of the finest parts in
tranquil water. The small shells and shelly powder sometimes seen be-
tween these layers of clay marl, were brought and deposited during other
intervals of more agitated water. I have often seen such deposits of per-
fect true marl, artificially produced, in the small open drains of marl-pits
(of our fossil shells), by the gradual settling of the suspended fine earthy
matters from the turbid water.

CLASSIFICATION OF MARLS.

431

■^

I. stony
texture.

1. Lime-stone proper,

2. Marl-stone.

3. Recent oyster or other hard sheila.

fl. Chalk.

2. Impure chalk.

3. Travertin or calcareous tufa.

4. Argillo-calcareous marl, or true

marl (of mineralogists).

II. Earthy
texture,

or marl in
general ■
and in

most ex-
tended

5. Shelly sea-sand.

L6. Shell-marl.

A. Fossil
fresh-water

shells.

B. Tertiary
fossil sea-
shells.

a. Sandy mi-
oeene marl.

I h. Clayey mi-
[^ ocene marl.

C c. Calcareous
eocene marl,
with very lit-
tle if any
green-sand.

d. Calcareous
matter and
green-sand,
both consi-
derable.

tw

e. Gypseous
or green-
sand earth,
with little if
any calca-
l^reous matter.

432

This plan of classification has reference to the agricultural or
manuring characters only of the substances named. Those which
dounot come under the head of marl, in the extended sense adopted
above, and which are not important in -Virginia^ will be dismissed
with but slight notice.

The general and very comprehensive term calx is here used to
include every natural (or indeed artificial) formation of earth, stone,
or shells, separate or in mixture, in which carbonate of lime is a
considerable and the most important part. All such substances be-
long to one or the other of the two great divisions — I., of stony hard-
ness, and II., of softer or earthy texture.

I. The stony bodies require to be burnt to quick -lime, to be
used profitably as manure. Such are, 1, compact or ordinary lime-
stones ; 2, marl-stone, or the hardest and largest stony nodules or
continuous layers in softer marl ; and 3, oyster or other recent and
hard shells.

II. The calcareous substances of earthy texture, soft enough to
be used as manures, without being reduced by calcination, all come
under the general and extended term marl, as here used. The
most important substances to be included under this head, are the
following : —

1. Chalk proper (nearly pure carbonate of lime), such as is
abundant in parts of England and France, is said by geologists not
to exist in North America. But there is what may be deemed, in
agricultural sense, an impure chalk, (2,) which spreads over or un-
der an immense extent of this continent. This is in Alabama and
Mississippi called ^' rotten limestone." It underlies, in beds of se-
veral hundred feet of thickness, large portions of these states, and of
Florida and Arkansas ; much of Texas, and, as I believe, most of
the vast prairie region between the Mississippi river and the Rocky
Mountains. This earth, so far as known to me by specimens only,
is composed of carbonate of lime principally, but with some 20 to
35 per cent, of cla3^ It is of a dingy whitish colour when dry ; ha.s
about the degree of hardness of chalk, to which th'is earth approaches
more nearly in composition, texture, and colour, than to either lime-
stone or to true marl. It may be inferred from the words of de-
scription in Fremont's Report, that this is the earth which forms
the great region through which part of the river Platte passes, and
which is found from the lowest visible depths to the summits of the
crumbling cliffs, some of which are many hundreds of feet high, so
remarkable along the banks of that river. I further infer that it is
this chalky and highly calcareous character of the surface-soil and
sub-soil which renders this region generally so barren, and usually
80 destitute of water ; while the continual crumbling of the banks of
the same barren earth into the river, and the earth being carried
down by the floods, intermixed with other suspended earths, and

TRAVERTIN AND ARGILLO-CALCAREOUS MARL. 433

finally deposited upon the lands flooded by the Mississippi, serve to
constitute the wonderfully fertile borders of that river.

3. Travertin, or calcareous tufa, is another subject of the many
provincial and improper applications of the term marl. It is tho
deposit made by the precipitation of carbonate of lime from its
previous solution in lime-stone water. The rain-water, in falling
through the atmosphere, absorbs carbonic acid ; which impregnation
enables water to dissolve and hold in solution carbonate of lime,
with which the water meets in abundance in lime-stone regions.
Thus the springs and streams of lime-stone water are produced.
But the carbonic acid absorbed by the water is retained with but
little force, and parted with to the atmosphere very easily. This
occurs wherever the water, so charged, is in contact with the at-
mosphere ; and consequently the more in proportion to the exposure
of its surface by the agitation of the water. Hence, at rapids and
cascades of lime-stone streams, this precipitation is always found
most abundant; and sometimes in immense quantity. It is prin-
cipally of carbonate of lime (about 70 or 75 per cent, in the trials
I have made), of cellular and open, though hard consistence, when
of newest formation, and not difficult to reduce ; and much more
loose and soft in other cases. This deposit will be found the cheapest,
and also a very rich calcareous manure (though never yet used, to
my knowledge), for the neighbouring lands. It is the product only
of lime-stone streams, either ancient or existing.

4. Argillo-calcareous marl, or true marl, has already been de-
scribed, as to its texture and constitution. This marl is not pro-^
perly shelly, though shells may be accidentally intermixed during
the deposition. Nor can any coarse or separate sand belong to it,
nor any other coarse and heavy matters, which would not remain sus-
pended in water flowing with but a moderate current.

This true marl is formed by the washing away and suspension
of calcareous and other earth in the waters of transient land
floods of rain-waters, or of rapid rivers and smaller streams. Tho
finer parts only of the different earths can remain long suspended
in the flowing waters, after the current ceases to be violent. These
finest parts of all, aluminous and silicious as well as calcareous,, are
most intimately mixed, and chemically combined, while suspended;
and finally are deposited in the form and quality of marl, when
reaching a lake, or other comparatively still part of the water. Of
course no such marl could have been formed unless the source of
original supply of materials existed, and also the manner of abra-
sion, transportation, and subsidence ; and no such source of calca-
reous earth could be presented except in higher chalk or chalky
beds, or otherwise highly calcareous soils and sub-soils. Compact
lime-stone alone, no matter how abundant, because of its hardness,
could scarcely serve as a source of supplv. It follows, that such
37

434 SHELL SAND — FRESH-WATER SHELL MARL.

marl may be presumed to l^ave been found and to exist in the
places of ancient lakes, or other still waters, in all chalk regions —
in the vast " rotten lime-stone'^ and prairie region of the southern
and western (or interior) parts of North America^ — rarely, if ever,
in our mountain lime-stone region, and certainly never in our tide-
water region. The calcareous beds of the tide-water region have
entirely a different origin, having been originally deposited or
formed and grown on the bottom of the ancient ocean, and since
upheaved to their present higher elevation. And it would be as
useless to search for the latter formation in the higher country.
Hence, the geological character of any region will indicate very
accurately whether either one, and which of these kinds of marl^
or neither of them, can be found.

5. Sea-sand is used to great advantage as manure in some parts
of France, and Britain and Ireland. A large, and sometimes the
larger part of this sand consists of finely reduced shells, rubbed to
granular state by the power of the waves } and this calcareous in-
gredient is the all-important fertilizing part of this manure, though
its operation and even its presence may be sometimes unknown to
the ignorant users.*

6. Shell marl may be divided into (A) fossil fresh-water shell
marl, and (B) fossil sea-shell marl.

A. The first of these kinds is what is usually, if not always,
understood by the name ^' shell marl'' by English writers. It is
formed by the gradual accumulation of the shells of small fresh-
water shell-fish, of existing species, on the bottoms of the shallow
lakes and ponds where the animals had lived and died. When the
bottom had been raised by this long-continued accumulation, and
perhaps increased by like deposits washed from higher sources,
nearly to the level of the surface of the water, then water-plants"
began to grow and to form a new accumulation of vegetable matter,
intermixed with the continuing deposits of earthy matter from
occasional turbid floods. Finally, by these means, the lake was
changed to a peat-bog, wet and miry, though usually free from
standing water. It is usually under peat, and sometimes at con-
siderable depths, that this peculiar and very rich calcareous manure
is found. It is almost pure carbonate of lime. It has been sold
in Scotland by the bushel, at a high price, and in great quantity,
for manure.f

* A notice of the English sand, showing old opinions of its value and
operation, was quoted at page 381 of this Essay.

f In the Edinburgh Farmers' Magazine, vol. iv. p. 153, there is an inte-
lesting article (most of which was republished in the Farmers' Register,
vol. i. p. 90), describing a large body of this kind of shell marl, under
Resteneth peat-moss, Forfar, Scotland. Most of the shells are of the wa-

TERTL^JlY SHELL MARL. 435

This formation, has been found in Vermont, in western New
York, and probably exists in many parts of all the other northern
states. I have never heard of its existence in Virginia, but infer
that it is to be found in the western and mountainous region. It
may be sought for with the greatest probability of success, in
regions where ancient lakes or pools had been filled by gradual de-
positions— and especially if such waters had been impregnated by
carbonate of lime, affording abundant supply of material for the
shells of the animals. A cool and moist mountain region also
favours the formation of peat. The presence of this substance is
connected with that of such shelly deposits below only so far a3
this : that the collections of waters which would produce and
finally be filled up by the gradual deposition of shells, in such a
climate, would be most apt to invite the formation of peat subse-
quently. Therefore, under peat, if in hollows, the deposits of such
shell marl are most likely to be found.

B. Tertiary fossil sea-sTiell Mart.

The second division of shell marl is the great and almost only
marl of the tide-water region of Virginia — and also of Maryland,
the Carolinas, and Georgia. It was produced by the gradual depo-
sition and accumulation of the shells left by the animals, mostly of
species now extinct, which had lived and died in them, on the bot-
tom of the ancient ocean. This former bottom of the ocean was
subsequently elevated, by some great conVulsion of the earth, much
above the original level, and generally much higher than the sur-
face of the ocean waters. Thus, these wide-spread beds of shells,
with the various admixtures of sand, clay, or pulverized shells,
brought by currents, or the force of the waves, became high land;
and the different conditions and qualities are such as might be in-
ferred from the different operations of the original producing
causes, with the additional aid of a subsequent state of rest for
countless ages. After the production and accumulation of these
beds of shells, to depths varying with circumstances, a mighty
flood, proceeding from the direction of the present higher lands,
swept over this great region, washing off and carrying away much
of the higher parts of these shelly beds, and then covering the re-
mainder with the drift of various earths brought and deposited by
this great land flood. Thus the beds of fossil sea-shells are gene-
rally thin in lower Virginia, and entirely wanting in many and
wide intervals ; and are mostly covered by a far greater thickness

ter snail (helix puiris, Linnaeus), others are bivalves (generally tellina, ani-
mal tethys, Lin.) From this deposit, the proprietor had sold as much for
manure as brought him £12,000 sterling, in the twelve yeays after its use
had been begun.

436 SHELL MARL OF VIRGINIA.

of layers of drifted and barren sands or clays, or both, with a sur-
face-soil usually poor and thin. Farther south, the denuding and
destructive power of this flood was so much less, that the shell
bed is left several hundred feet in thickness. In Virginia, the re-
maining bed is in most cases less than fifteen feet in thickness,
and rarely much more.

As there is good reason for believing that all the present great
tide-water region of the countries last named was formerly the
bottom of the ocean, for an immense length of time, we may in-
fer that the whole was originally covered, to greater or less depth,
with a continuous bed of shells. Wherever this formation is now
wanting, it must have been removed by the subsequent washing
flood, previous to its later action of depositing the enormous bed
of drifted earth, which overlies the shells, or their former place.

The fossil shell beds of Virginia, which will be the main subject
to be treated of here, may be again conveniently divided, for de-
scription and observation, into two kinds, of (B 1) Miocene, and
(B 2) Eocene. These terms (with others) were introduced by
Professor Lyell, and designate the formations of difiierent geologi-
cal eras. As they are now of general acceptation by geologists,
and also are generally understood by agricultural readers, these
terms will be convenient, and will be here used to designate the
difi'erent marls to which they belong. If the dificrence between
these two kinds were merely geological, or in regard to comparative
ages of formation, or to the respective fossils of each, it would be
useless to preserve it in writing on agriculture, however marked the
difference, and however interesting to the geologist. But there is
also a difference of agricultural character and value in these two
kinds of marl. In relation merely to each other, the terms eocene
and miocene may be sufficiently understood as the older and newer
formations. But it will not do as well to substitute the latter
terms, because, though correct as to each other, they are not so
generally, or in relation to other marls and geological formations.
For there are some (of secondary formation) much older than the
eocene, and others (older and newer pliocenes and post-pliocene)
much more recently formed than the miocene. With neither of
these is it necessary to encumber this report, by other than slight
notice, as neither are known in Virginia; nor elsewhere do they
present important differences of agricultural character and qualities.

The different periods of time of these two different deposits of
shells were very remote from each other, and the latest of them
was also very remote from the present time. In the miocene marl
of Virginia, or later of the two, of the numerous species of shells
found, there are but few kinds belonging to races of animals known
or believed to be yet existing ; and in the eocene marl of Virginia
there are almost none that now exist, and very few that belong

MIOCENE MARL. 437

also to tlie miocene marls. According to the highest geological
authority, most of the races of animals whose remains formed the
latest as well as the earliest of these deposits, were extinct before
the creation of man.

Although it might be more conformable to regular or scientific
arrangement to commence a general description with the older and
lower deposit, the eocene marls, yet it will better suit the purpose
of agricultural instruction to reverse the order, by describing first
the miocene marls, as the highest in the series and the first reached,
and by very far the most abundant and extensively accessible ; and
which, therefore, though usually less powerful for fertilization, are
much the most important to agriculture in Virginia in general. I
shall therefore proceed first to treat of the miocene marls, which
are the only kinds known to me in Virginia, with the exceptions
of the two comparatively small districts of eocene marl, which will
be hereafter treated of in their order.

Miocene Marls.

When my investigations and practical labours on this subject
were commenced, more than twenty-four years ago (in 1818), the
existence of marl of any kind, or rather its shells, obvious to the
sight, had been noticed in lower Virginia at but a few places, where
naturally exposed along steep river banks, and where cut through
by deep ravines, and thus rendered conspicuous ; and the deposit
was supposed to be very limited, by the few persons who had ever
cast a thought upon the subject. But the attention and observa-
tion subsequently directed to the search, soon showed that the
quantity was very far more extensive ; and now, though not gene-
rally near the surface of the earth, nor everywhere accessible, it
seems probable that beds of fossil shells underlie much the greater
part of all the region between the falls of the rivers and the sea-
shore. Except at or near the places where exposed on the surface,
as above mentioned, the overlying (drift) earth is generally 20 or
30 and sometimes even 50 feet thick. All the marl-beds appear to
be nearly horizontal, and of course are the most deeply covered
under the highest lands, and are most easily accessible in low de-
pressions. The deposit dips gently towards the east, so that it lies
too deep to be visible near the sea-coast. At Norfolk, the marl
has been recently reached, in boring deep for water, at 40 feet be-
low that low surface, and, of course, much below the sea.

The marl is formed by the deposit and gradual accumulation of
sea-shells, mostly left where the animals died ; and the vacancies
between the shells were filled by the sand or clay, or mixtures of
both, with fragments of older shells, brought by tide and currents,
and deposited in what was then the bottom of the sea. The re-
markably perfect state of preservation of many very thin and
37*

438 MIOCENE MARL.

always fragile shells, and still more the many pairs of bivalve shells
that yet are found connected or in contact, prove that such shells
could not have been transported, or even much agitated, by the
force of the water. But other beds of marl, and also frequently
the upper layers of such as have been just referred to, show as
clearly the action of currents, or of water in violent and long-con-
tinued motion, which served to grind down the shells to small
fragments, and which also left, in shaping the surface of the marl,
the marks of whirlpools or other violent disturbance. From such
supposed causes might be expected such effects as many of the
various marl-beds actually exhibit. In different places, and some-
times in the same place, the shells and their fragments are found
of all sizes, and of all conditions of preservation ; and intermixed,
in various proportions, with such clay, or fine sand, as might be
suspended in or borne by currents, or waves of the sea ; so as to
form beds of every degree of texture and shade of colour. The
shells, and their fragments, or the carbonate of lime, are in
various proportions of quantity, from 10 per cent, (or even less in
rare cases) to 90 per cent, or more, of the mixture, or whole mass.
In different beds, and sometimes in contiguous layers of the same
bed, the shells are in every state of preservation or of decay ; from
that of being firm, and often entire in their calcareous structure,
and the most delicate parts of their beautiful forms preserved, to
that of being mostly broken down, and almost reduced to a coarse
powder, and sometimes even forming a homogeneous mass of still
finer particles, in which the forms of but few if any shells are dis-
tinguishable. The original bright and various colours of the shells
are lost, and they are nearly all white — a few of the hardest kinds
only being brown or gray. The texture of the mass also varies,
from a loose sand to a firm body of almost stony hardness. The
earth intermixed with the shells is generally much more sandy
than clayey, and more especially in the poorer marls. Even when
the admixture of earth is clay, it rarely makes the marl appear the
least clayey in texture, or plastic or adhesive, because the clay is
usually but in small proportion to the shelly matter. Even when
the proportion of clay is great, the carbonate of lime, according to
its quantity and degree of reduction, counteracts the tendency of
the clay, and prevents the mass being tough, adhesive, or obdurate.
The colour of the miocene marls is also various — generally either
pale yellow or dingy white, or blue, sometimes bright, but more
often a dull blue, or ash colour. The richest marls, of homogene-
ous texture, are nearly white when dry, and approach in appear-
ance to a coarse or impure chalk.

The shell marls of Virginia are confined almost entirely to the
tide-water region, or the space eastward of the granite which forms
the falls of all our eastern rivers. But near Petersburg (on the

MIOCENE MARL. 439

farm of Dr. William I. Dupuy, and other adjoining lands) there
is an exception to this general rule, the marl being found about a
mile farther west, overlapping the eastern and lowest part of the
granite, and passing under a small stream which empties into the
Appomattox, a mile above the lowest falls.

The only important fertilizing ingredient of the miocene marls is
the carbonate of lime, or shelly matter. There may be, and proba-
bly is, some slight additional benefit sometimes, from accidental or
peculiar admixtures of other substances ; as, of animal matter still
remaining, or, in limited spaces, the phosphate of lime supplied by
bones of large fish or sea reptiles j or of vegetable extract in blue
marls, of the oxide of iron, of a very small proportion of green-
sand generally; and even of the clay or the sand, respectively for
soils deficient in either. But either and all of these additional mat-
ters, though giving some value as manure, are of but little im-
portance in miocene marls, in comparison to the main and great
agent of fertilization, the shelly or calcareous matter. According
then to the greater or less proportion of this main ingredient, and
to its state of division or readiness to be reduced to a state of mi-
nute division in the soil, may be rated the comparative values of
marls for manure. In regard to the much larger proportions of
green-sand in miocene marls, as asserted by other authority, and de-
nied by me, some additional remarks will be hereafter submitted, in
the proper order for consideration.

As might be inferred from the obvious manner of the deposition
of the marl, as before stated, by waters of the sea in violent and
yet varying degrees of motion, the diflferent horizontal layers of
marl, successively deposited in the same bed, and even within a few
inches of perpendicular distance of each other, sometimes exhibit
remarkable differences of appearance, composition, and of value ;
while there is also generally as remarkable a uniformity of charac-
ter of each particular layer (though differing much in thickness at
different places) throughout not only the different diggings of the
same place, but sometimes for miles in extent. I have seen often,
in diggings on different farms, and several miles apart, layers of
marl so precisely alike, and so marked in peculiar character, that
there could be no doubt of their being parts of the same particular
deposit, made at the same time, and by the same operating natural
causes. Under such circumstances, a practised eye can by com-
parison fix very nearly the chemical composition of similar varie-
ties, and even more correctly, for general averages of value, than
would be usually obtained from the accurate chemical analysis of
one or two specimens only. For the usual danger of error is, not
in the chemical analysis (which is easily enough made, and the
mode sufficiently correct), but in the selection of equal and fair
specimens of marl to exhibit the average strength of the whole body

440 MIOCENE MARL.

excavated ; which requires much more experience and accuracy than
are usually exercised by most operators, and still more in regard to
proprietors who send specimens of their marls to be analyzed by
other persons. It is highly important to the farmer to know the
strength of the marl he is using. And to this end, it is necessary
that every layer should be carefully analyzed, or, what is better, a
specimen from an equal and continuous shaving of the whole ver-
tical section of a digging, so as to furnish a fair average of the whole
body. But after this trouble is once taken, the general result will
serve for all the future diggings at the same place, and also for
similar bodies more or less remote.

The layers of marls formed by shells left " in place," or where
the animals died, are in general the poorest ; and for this obvious
reason, that all the hollows of and interstices between the shells are
filled by what is mostly earth (but mixed with more or less of shelly
fragments), and that earth is principally silicious sand. Marl so
formed, will not have more than 35 to at most 40 per cent, of cal-
careous matter, and more often only from 25 to 35. The sand or
earth that would be required to fill all the hollows and chinks of a
body of entire shells, of ordinary form, though touching each other
at their edges and points, would necessarily be as much as 65 to 75
per cent, of the whole mass. And therefore, it is only because of,
and in proportion to, the quantity of shelly particles mixed and
borne along with the earth brought by currents and deposited among
the whole shells, that such marl is sometimes richer than 25 to 35
per cent, in calcareous matter. The degree of admixture of shelly
fragments in this filling earth, may be easily judged of by an expe-
rienced eye, and the proportion of shells and large fragments will
depend much on the forms of the prevailing kinds of shells. It is
easy to know the marls formed by shells left in their original place,
by the state of the shells. Either the shells being whole, and es-
pecially the more fragile varieties, or the two sides of bivalve shells
being found in close contact, as when the animal was living, will
show clearly that the dead shells had not been much agitated, or
borne along by currents. The beds or layers formed by removal,
are as easily known by the broken and finely reduced state of the
shells. These marls are usually much the richest in calcareous
matter; for, by the grinding operation of the currents, and the
difference of specific gravity in the particles carried along, the cal-
careous powder and clay are deposited together, with but little sili-
cious sand. Among the richest marls are some having whole shells
in their original places, but of which the interstices are filled by
such fine calcareous and clayey earth as could have been deposited
only in waters nearly still. Such are the rich marls in and about
Williamsburg, and in Surry, and that belt of country generally, con-
taining 70 to 80 per cent, of carbonate of lime.

VARIETIES OP MIOCENE MARL. . 441

The different varieties of miocene marls, which will now be more
particularly described, are not always separated in different beds,
but sometimes form some of the different and even adjoining layers
of the same bed or digging. The differences of colour, &c., caused
by the greater or less quantity of various accidental ingredients,
however striking to the eye, are not often of much importance to
the value of the marl } but only (or principally) such differences as
are caused by the greater or less proportion of shelly matter, and
its state of disintegration and division.

Brownish yellow marl. — This kind, wherever found, always
forms the highest layers of the particular body. That is, if there
be layers both of yellow and blue marl in the same body, the yel-
low is always above and the blue below, and never in the reverse po-
sition. But sometimes the yellow continues to the bottom, and
sometimes the blue forms the top as well as the bottom.

Yellow marl is usually found dry ; that is, having no springs or
oozing waters, which are generally reached on digging lower in the
body. But the lower part, where wet, is sometimes, though rarely,
of the same yellowish or dingy white tint, so as to make it manifest
that the colour is not dependent on the degree of moisture or dry-
ness. The yellowish tint is owing to the presence of oxide of iron,
and is pale or deep, approaching sometimes to reddish brown, ac-
cording to the quantity of that colouring matter.

Yelloio sandy marl is the kind most abundant in Prince George
county on and at some miles distance from the banks of James river,
and from which some farms entirely, and others principally, in that
neighbourhood, have been marled. It is of shells left in their original
place, the filling earth being mostly of coarse sand, and the whole
body poor in calcareous matter, varying in its proportion usually
from 20 to 30 per cent, and rarely richer than 35 per cent. But it
is of such open and loose texture (and the more so as the sand is the
more abundant), that this marl is easily and cheaply worked, and
the labour so applied is therefore often better compensated than in
diggings of much richer marl. In this variety of marl, the shells
are usually entire, or in large fragments, but are not firm or well
preserved. In some beds, or thick layers, they are so finely reduced
that the mass seems to the eye to be wholly, as it is indeed prin-
cipally, a body of silicious sand. From one bed of this kind, which
its proprietor supposed from its appearance to be merely silicious,
the earth was used as sand to mix in lime-mortar for masonry, and
it was found to serve well for that purpose. Subsequently this
bed of sand was found to be enough calcareous to be used as manure ;
and was so used, and to such good profit, that the proprietor sup-
posed it to be rich marl. In that opinion, however, he was mis-
taken, at least as to the proportion of calcareous contents.

Yellow clay marl. — But most of the richest as well as of the

4'i2 VARIETIES.

poorest miocene marls, are yellowisli. "When rich, say containing
proportions of carbonate of lime from 45 to 80 per cent., the marl
is usually formed of shells broken down, when under the sea, to
small fragments or to powder, by the grinding action of the water
in violent motion, and left afterwards to settle in stiller water, ac-
cording to the specific gravity. Or it is the same kind of rich and
finely divided water-borne matter deposited on and filling the hol-
lows in and between whole shells remaining in their V)riginal
place. In either case, the small quantity of earth first suspended
in the current, and then deposited with the finely reduced shelly
matter, is mostly if not entirely clay ; as silicious sand, having more
specific weight, could not be suspended by the current so long, or
carried so far, before being deposited. The few rich clay marls of
Prince Greorge are of the first-named variety, or composed entirely
of fine fragments of shells intermixed with clay. The much richer
marls in and about Williamsburg are of the other kind, there being
also numerous whole shells in place, as well as the interstices being
filled almost entirely by water-borne fragments, and fine powder of
other shells. The other contents, making from 15 to 25 per cent.
of the body, are principally of a very fine clay of pale yellow, and
much less of silicious or white quartz sand, oxide of iron, and a
little green-sand. Much of the same kind of rich marl is also in
other parts of James City and York, in the lower part of Surry,
and in Isle of Wight, New Kent, and King William counties, which
I have seen — and probably throughout the middle belt of the marl
region of Virginia. There has been little or none of this rich clay
marl seen by me in the upper range of marl counties (those next
the falls of the rivers), and not much more near to the eastern
limits, or next to where the marl dips so deeply, as to disappear
from the surface, and is accessible only by deep digging. Perhaps
observations more extended than mine have been, might present
difierent conclusions.

The rich marls just described, when separated mechanically (by
the sieve, and by carefully washing in water), seem to consist, for
the much greater part, of pure shelly matter, mostly in large or
small fragments, slightly coloured brown by oxide of iron, and the
remainder of a very fine and apparently pure pale yellow clay. But
this clay is also composed in part of finely divided carbonate of
lime; and the fine shelly matter is intermixed with some silicious
sand and a little green-sand. The bed of marl near Surry Court
House (which is similar to the marl at most other places thereabout)
is of this kind and general character ; and from it, a large body of
land has been manured with great benefit. This body of marl was
reputed, upon the authority of the State Geological Surveyor, to be
among the richest in green-sand. From a much larger sample of
the marl of this bed; carefully selected by the proprietor, at my re-

i

RICHEST MIOCENE MAULS. 443

quest, and for my examination, an average portion taken was com-
posed as follows : —

1780 grains, separated mechanically, by the sieve and by washino"
and subsidence in water, consisted of

Carbonate Fine argillaceoTis Silicious Green-sand,
of lime. oarth. sand.

1036 grains of shells and coarse
fragments, nearly pure, and
so coanted, - - 1036

483 grains of fine shelly frag- *

ments, &c., which consisted

of - - - - 268 - - - 120 45

277 grains fine yellow clay, &c.,

which consisted of - 65 - 212

34 loss in the process.

1780 • 1369 212 120 45
Which may be stated of parts to the hundred, thus :

100 grains of marl contained of carbonate of lime, - 77 grains.

Silicious or quartz sand, very pure and white, - - 6| "

Green-sand, -____>__ 2|-"
Fine yellow clay or argillaceous earth (and the loss in

the latter process), .-_>._ 13| a

100 "

The richest bodies of these marls show very few shells, or even
fragments, and have a homogeneous texture and appearance to the
eye, like a very impure chalk or sandy clay. Such marls are
found in James City, New Kent, King William, and Middlesex
counties. The following are some of them of which I have analyzed
specimens : —

moM
King William, (Lipscomb's land) — 82 pr. ct. of carbonate of lime.

" (Slaughter's land)— 88 " " "

New Kent, (Mount Prospect)— 88 " " "

Middlesex, (Oaks' land)— 83 " " "

Most of these marls are soft enough to be used for manure as
dug from the pits ; but the hardest lumps may need burning to
lime. Any marl hard enough to need burning, and as rich
as 85 per cent., will make good lime for cement, as well as for
manure,

Under a peculiar combination of circumstances, the great rich-
ness of some marls operates to lessen the value of the body as ma-
nure. Rain-water, when just fallen, always contains come carbonic
acid, which admixture causes it to be a solvent of carbonate of lime.
When rain-water then can descend by percolation into rich dry
marl, in its passage it dissolves some of the calcareous matter.

444 CRYSTALLIZATION OP MARL.

"which is again left solid, and in crystals, by the slow evaporation
of the fluid. These crystals of carbonate of lime are slowly added
to by every recurrence of the like causes, until the cavities of large
shells, and other openings into which the water had settled, are
completely filled with crystallization. If layers of marl, less per-
vious to water than in general, oppose the descent of the water, the
crystallization forms in connected horizontal layers, separated by
the thicker layers of softer marl. Such crystallized layers are
4)und abundantly in the very rich marl in the cliiFs at Yorktown,
serving by their stony hardness to impair the otherwise great value
of the manure. At Belfield, Col. Robert McCandlish's farm, a few
miles higher on York river, the hollows of large shells have been
filled with beautiful and brilliant crystals thus formed. In Surry
also, on the land of the late William Jones, such crystallization is
abundant. For such effect to be produced, there are several con-
ditions necessary. The superincumbent earth must be of open
texture, and not very thick — or rain-water could not pass through.
It must not be a hill-side — as the water would flow off the surface
and not penetrate to the marl. And the marl must be dry — or
evaporation could not take place, and, of course, crystallization
could not.

Gloucester, though one of the outside marl counties to the east,
is most abundantly supplied with marl, accessible on almost every
farm, whether of high or of low grounds. It is generally of the
poorer yellow kind. But three marked exceptions were seen,
which as such deserve to be named. One is the rich clay marl
forming the north bank of Ware river on the farm of Mr. Alexan-
der Taliaferro. Another is the general sub-soil (as it may be con-
sidered from its position) of the lowest land of the farm of Mr.
Jefferson Sinclair, near the mouth of Severn river. This is an al-
most pure body of coarse shelly powder, or fragments, seldom found
larger than two or three grains in weight, and a very few shells, of
as minute size, entire enough to be distinguished. This mass of
shelly matter is as loose and incohesive as coarse sand, yet is tinged
slightly with green by the admixture of greenish clay. A speci-
men analyzed contained 72 per cent, of carbonate of lime. (See
more full account at page 181, vol. vi. Farmers' Register). The
third is the marl used by Capt. P. E. Tabb, and dug from beneath
the low grounds on North river. It is a mass of pulverized shells,
coloured by red or brown oxide of iron.*

Blue marl. — This is the most common kind in the upper range,
or near the western limits of the great marl deposit. Thereabout,

"^ This is the marl so abundant, and of easy access, on Toddsbury, the
property and residence of the deceased Philip Tabb ; and of which marl the
value as manure had not been tried, or suspected, by that experienced and
deservedly distinguished farmer, during his long life on that farm.

BLUE MARL. 445

Hue marl usually forms the whole thickness of the bed. More
eastward, and lower down the country, it sometimes forms the
whole of low-lying beds, but more usually only the lower layers of a
bed, of which the upper part is yellow.

Blue marl is generally such as remains " in place,'' or where the
shells were left by the death of the enclosed animals, and the inter-
mixed earth is mostly silicious sand ; and therefore (and not because
of its colour), this marl is rarely found as rich as 45 per cent., and
is still more rarely equal to the yellow clay marls, though generally
richer than the yellow sandy marls.

Blue marl in the bed is always wet, being made so by water
slowly oozing from every part, though seldom fast anywhere, or
showing springs or veins of running water. The blue colour is not
caused by moisture (for some yellow marls are also permanently
wet), but by vegetable extract or other dark-coloured organic mat-
ter, brought in the percolating water. This inference I have drawn
from extensive observation of the natural beds, and also from seve-
ral accurate though accidental experiments, of which the first that
was observed will be here stated. A small stable yard was covered
6 to 10 inches thick with a rich dry yellow marl, for the purpose
of retaining by chemical combination the juices of the putrescent
manure which was to be thrown there from the stable. After re-
maining for this use a year or more, this flooring of marl was dug
up and carried out for manure ; when it was found to be changed
in colour to a deep and vivid blue, and precisely like the natural
colour and appearance of the under-stratum of the same body of
marl, which being an open and almost pure mass of pulverized (and
water-borne) fragments of shells, was readily penetrated by and
always full of water. A general fact confirming this view is that
all marls found lying immediately under swampy soils, full of
vegetable matter, are blue. And this colouring vegetable matter
in marl is not merely intermixed with, but must be held in chemi-
cal combination by the calcareous matter; and serves, according to
its quantity, in blue marls, as an addition to the fertilizing power
of the calcareous matter alone. The particular body of marl above
referred to, the under-stratum of which is the most marked or vivid
blue ever seen in marl, is at Shellbanks farm, Prince G-eorge, and
from which I dug and applied a large quantity. The greater part,
and all the richest layers, seemed to be of shells broken down to a
coarse powder, or of sizes less than fine gravel, through which clear
water rose and passed so freely as to forbid digging to the bottom.
The small quantity of clay or other earth intermixed with the cal-
careous earth of this marl is altogether insufiicient to hold so much
colouring matter; and moreover, if the colouring matter were not
chemically combined with the calcareous, the continued free pas-
gage of water must have dissolved and washed off any uncombined
38

446 BLUE MARL.

vegetable extract. This whole body of marl, both the dry and yel-
low lying at top, as well as the blue and wet below, was all brought
and deposited by currents, as is manifest by the different layers of
different specific gravity, and still more by the many intervening
layers of a fine calcareous clay (before mentioned), which may be
considered as the true marl of mineralogy, though in very small
quantity. Analyses were carefully made of every different quality,
and the refsults may be interesting as showing how much one layer
may vary from the one next adjoining; and different specimens not
more than a few inches of perpendicular distance apart.

Upper dry part, yellow, and loose as sand, varying
(by unevenness of surface) from 3 to 7 feet, con-
tained of carbonate of lime . . . .53 per cent.

Next layer below, brownish yellow, through which

water passes, ...... 25 "

About 12 inches lower, in the blue, . . .64 "
" " ^' " '^ " another specimen

below ........ 69 "

Layers of clay marl, interspersed through the above 9 "

And in a subsequent digging, the strength of four specimens of
the blue part of the marl was as follows : —

In the first foot depth of blue under-stratum . 32 per cent.

In the second foot 33 "

At 3J feet 76 "

At 4 feet, and lowest digging then effected . 70 '^

It may readily be inferred, from these various results, that if
one or two specimens only had been analyzed, and these taken with
no more care than is commonly used, that a very deceptions report
would have been furnished from making even the most accurate
analyses.

Conchologists and geologists, who have treated so much of marls,
but merely in reference to the shells they furnish, or to their
geological character, speak of the blue marl as formed by shells
being imbedded in a blue clay. But the earth is not generally a
clay, nor anything even approaching to a clay, but is mostly of
silicious sand. The ordinary blue marl contains usually from three
to four times as much pure and separable silicious sand as of clay.
From various specimens of two diggings in such marl, from which
more than 300 acres were marled of the Coggins Point farm, the
following results were found by analysis : —

Yellow marl (wet) thin layer at top, contained of car-
bonate of lime ,,,.., 24 grains.

BLUE MARL. 447

Within 24 inches of top, shelly matter finely divided, and the
mass uniform dull blue colour, 100 grains contained :

Carbonate of lime, 34 grains.

White silicious sand, 47 "

Clay, black when moist, and dark gray when dried, 19 "

100
Of similar blue marl from another pit in the same body, 100
grains contained :
Carbonate of lime, ...... 34 grains.

Silicious sand, 52 "

Clay, 14 '^

100

Of another specimen from the same, and of similar

marl, 100 grains contained of carbonate of lime, 29 '^

At 6 feet deep (the shell not much reduced), carbo-
nate of lime ....... 44 "

At 13 feet deep, and one foot from bottom, . . 33 "

Some few hard lumps of conglomerated shells and

earth scattered through the general mass, . 73 "

From a digging at three-fourths of a mile distant, of marl of the
same appearance and believed to be the same body as the preceding,
the general average of strength, as obtained from several trials at
diiferent depths, was in 100 grains of marl, 35 of carbonate of lime.
The thickness of this body, where penetrated, varied from 11 to 14
feet ', where there was a marked lessening, though not entire ab-
sence of shelly matter, and increase of silicious sand of the same
blue tint. The deeper removal was stopped because of the obvious
poverty, and no further examination of more than a foot or two in
depth was made in this poor substratum. In but few of all the
various diggings made by myself, or of others heard of, has the bot-
tom of the marl been reached — though in many, and most generally
when penetrated deeply enough, it becomes so poor as to be not
worth the labour of removing. In most of the few known cases,
when digging the marl for manure, that the bottom of the miocene
was reached, the stratum below was of eocene green-sand earth, or
eocene marl. In digging a well, at Shellbanks, my then residence,
after passing through a bed of firm blue marl, of broken (or water-
worn) shells, obviously the same kind dug at another place for ma-
nure, and described at page 445, a soft brown sand was reached,
apparently destitute of calcareous matter, and from which rose an
abundant supply of pure and soft water to the height of 13 feet,
which stood altogether in this blue marl, without its purity being
affected either by the calcareous matter of the marl, or its colour-

448 LOSS OP CALCAREOUS MATTER.

ing matter. The contimied purity of this water is an additional
proof that the blue colouring matter is chemically combined with
the carbonate of lime — and the combination is a visible illustra-
tion of the manner in which marl holds to and fixes putrescent
manures.

Mr. William Carmichael, of Queen Ann^s county, Maryland, an
intelligent agriculturist, and an experienced and observant marler,
is of opinion that there is a perceptible superiority of effect of blue
marls over others of equal (and even greater) strength in calcareous
matter. (Farmers' Register, vol. vii. p. 106.) This superiority
of effect probably is caused by-the vegetable or other putrescent and
alimentary matter being combined with the calcareous, and by its
presence giving colour to the blue marl. And that the blue colour
is thus produced is fully proved by the facts stated at page 445,
and by my more general observation.

Excepting then the additional value in the vegetable extract
which gives the colour, there is no difference between the blue and
the yellow marls, other than the difference, as of any marls of simi-
lar colour, in their respective amounts of calcareous matter. And
the same may be said of wet and dry marls, which are generally,
but not always, distinguished by the above colours ; and also of any
other miocene marls, excepting for such small proportion of " green-
sand" as is sometimes present. But there is reason to believe that
wet marls, in many cases, have lost some of their ancient strength,
by the continued though very slow percolation and subsequent dis-
charge of water through the mass. If recent rain-water penetrates
wet marl, it dissolves some carbonate of lime (by means of the car-
bonic acid in the rain-water) j and, as the water slowly flows off, or
oozes out, instead of being evaporated, the dissolved lime is washed
into the nearest stream, and is lost, instead of being left, crystal-
lized or otherwise, as in dry marl. Again — if water flows over
having sulphate of iron (copperas) in solution, (which is not a very
rare case,) that dissolved salt acts with the carbonate of lime to
produce the decomposition of both the sulphate of iron and the
carbonate of lime, and from two of their component parts to form
sulphate of lime. And as this is slightly soluble in water, it must
be carried off by the slowly oozing water, as long as any of these
new salts remain. In this case, the carbonic acid is evolved, and
the iron is precipitated — and often fills, or coats the interior of the
spaces before filled by the shells which this chemical process had
decomposed and removed. This effect, when produced, is seen at
the upper part of the marl, where the copperas water first touches
the shelly matter. In Henrico, near the western limit of the marl,
and in Hanover, more eastward, there is generally over the pre-
sent highest shells a body of earth of colour and general appear-
ance very similar to the marl below, and full of hollow impressions

COMPARATIVE VALUES OP MIOCENE MARLS. 449

of shells, though no shelly nor even any calcareous matter now
remains. In other marls, there is often seen an upper layer
coloured brown by this deposit of iron. Both these are different
modes of the same operation ; the waters charged with sulphate of
iron having in the latter case decomposed and removed but part,
and in the former all the calcareous matter, to some depth below
the former top of the stratum of marl. The marl, in the upper
part of which the shells have been thus dissolved and removed,
has a decided sulphureous odour, which is left very perceptible on
the hands, after handling the marl as dug ; and this odour is still
more manifest in the marl when it has been dug and thrown out,
and exposed some days to the weather. Such marl is within a few
miles of Richmond, at Dr. Chamberlayne's and Col. C. W. Gooch's
farms. It is poor in calcareous matter.

The comparative values of marls are fixed by the comparative
proportions of carbonate of lime contained, other circumstances
being alike ; yet if these other circumstances are very different,
they may make a marl containing but 25 per cent, worth more
than another of 50 per cent. The more finely reduced, or the more
soft the shells, the quicker the action will be, and the more profita-
ble the marling. But all the white shells, however hard and
entire when applied, are dissolved in a few years, if the soil really
needs so much lime — that is (according to my views), if there be
acid of soil enough to combine with the lime- But the gray or
slate-coloured shells seem to be insoluble and almost indestructible,
and do very little good as manure. These shells are the several
species of scallop (^pecteii) and of fossil oyster (ostred), and some
few others, all fortunately being but in small proportion compared
to the numerous white and softer shells. Some beds of marl,
however, or layers, have mostly these hard shells, and therefore
are worth very little compared to what their chemical analysis
would indicate.

It is not necessary to speak otherwise than very concisely as to
the practical applications and effects of miocene shell marl ; for
this is the kind in general use throughout lower Virginia and Mary-
land, and to such small extent as has been used in North Carolina,
and. therefore the operation is well known. All the usual and
general and highly beneficial effects of marl known, with but few
exceptions in the limited districts of eocene marl (hereafter to be
described), are due to the miocene marls. And of such effects
there have been numerous statements, general and particular. The
operation of the eocene marls, and especially those largely mixed
with " green-sand,' ' is different, and superior; but their use has
been so limited, and so few statements of effects published, that
nearly all the particular results and general statements of effects
38*

450 ' EOCENE MARL.

yet laid before the public, in the "Essay on Calcareous Manures'*
or elsewhere, have been in relation to the miooene marls.

My personal examinations of marl, in place, have not been ex-
tended to the Rappahannock. From such information as has
reached me, I infer that the marls of that basin are generally njuch
poorer in calcareous matter than those of the basins of James
river, York, Mobjack bay, and Piankatuck river.

Eocene Marl.

(c) Calcareous marl^ containing hut little green-sand. — The ex-
istence in Virginia of the marl now known as eocene, was first dis-
covered in 1819 by myself, in the south bank of James river, un-
derlying the promontory of Coggins Point ; and in the same year
it was tried as manure. The texture and general appearance of
this marl were obviously peculiar ; and its effects as manure were
soon also observed to be in some measure different from and supe-
rior to those of the other marls, which I had then used, and which
were all of the kind now distinguished as miocene. At that time
these terms had not been introduced, and for perhaps fifteen years
afterwards, I did not so much as hear of the terms " eocene" and
"miocene;'' but the difference of age, appearance, and agricultural
character of the two kinds were not therefore the less evident and
obvious to my uninstructed observation. The manifest difference
of effect, as manure, was then ascribed by me to the general if not
universal presence of a small proportion of sulphate of lime, or
gypsum, in the eocene marl. The belief in the general presence
of gypsum was very early induced by my seeing in a few places
small crystals overlying and in contact with the surface of the bed
of marl ; and also by the apparent results o$ such poor attempts
as I subsequently made to ascertain the presence of this substance,
by means of chemical tests. Upon such imperfect trials, and the
still more imperfect knowledge and skill which I could apply to the
investigation, very little reliance ought to have been placed. Never-
theless, I thence inferred that there was universally present and
diffused through the body of this marl a small proportion of sul-
phate of lime, and subsequent agricultural practice has supplied
the confirmation, which has not yet been sought for by the supe-
rior chemical knowledge and skill of any other and later investi-
gator. In the earliest publication of my views on calcareous ma-
nures in 1821, the gypseous character of this particular body of
marl was affirmed, and the peculiar character of the results of the
first experiments with it stated.* And in the edition of 1832 of
the "Essay on Calcareous Manures," the general and full descrip-

* American Farmer, vol. iii., p. 317, and also the same experiments nnm-
bered 18, 19, 20, of the present edition of <' Essay on Calcaxeons Manures."

EOCENE MARL OP COGGINS POINT. 451

tion of this marl was given precisely as it now stands in pages 144,
145, of the latest edition. My still earlier discovery of and ob-
servations upon the peculiar character of the underlying bed of
gypseous or ^^ green-sand" earth (which will be treated of subse-
quently), led me to observe the peculiarities of the eocene marl,
which being less distinctly marked, might otherwise have escaped
my notice.

As stated above, it was not from any knowledge of geological
theories of successive formations, and different ages and periods,
of all which I was profoundly ignorant, that my opinion of the
peculiar character of this marl was influenced. But judging
solely from the more rotten and disintegrated state of the shells,
and their entire disappearance generally, even though their calca-
reous material remains — and from the total difference of kind of
the few shells remaining whole, or of which the shape is distinctly
marked, from any others of the many shells then known to me in
any other marls, I very early formed the opinion that this bed was
one of the remains or ruins of a condition of the earth much more
ancient than that in which the ordinary marls had been formed.
I remember having stated this opinion to one of the earliest of the
several geologists who at different times visited my dwelling-place
and my marl excavations. This was the since notorious Feather-
stonhaugh, to whom I pointed out this curious and to me highly
interesting deposit, and directed his attention to the more modern
and very different (miocene) marl lying immediately upon and in
close contact with the mucJi more ancient formation below. This
remarkable feature I also showed at a later time to Professor AVil-
liam B. Rogers, who was much struck with the fact, and attached
so much importance to it, that he has referred to it in several of
his subsequent publications.

The most ready and certain mode of distinguishing eocene marl,
is by reference to some of the shells belonging to this kind, and
which are never found in miocene marls. There are many such ;
but the most common and well marked are the tvfo following : 1st.
The cardita planicosta, a bivalve white shell, having numerous re-
gularly formed flat ridges running from the point at the hinge of
the valves to the circumference of the outer or opening parts, and
widening as the ridges extend — both valves alike, and having out-
lines approaching to circular — sometimes seen four inches across,
and the connected valves two inches through ; but generally of
much smaller and various sizes. 2d. The ostrea sella:formis, or sad-
dle oyster, a curiously and variously contorted gray and very hard
bivalve shell, the larger valve of which approaches the shape and
reversed curves of a saddle. This shell is sometimes found more
than five inches in length. Both of these shells are abundant,
especially the cardita ^lanicosta, in this particular bed of eocene

462 EOCENE MARL.

marl, and also in the nj^er part of all tlie other eocene marls since
known elsewhere in Virginia. Without reference to these, or to
some other characteristic shells, the eocene marl might not always
be distinguishable by its texture or general appearance from the
miocene. And even these two shells, the most abundant and
characteristic of the eocene formation generally, are neither to be
found in the lower layers of any bed that I have been enabled to
examine.

For some years after the first discovery and application of this
calcareous eocene marl on Goggins Point farm, it was not known
to exist elsewhere. For even where then visible, and at later times
used, its different character was neither known nor suspected by
its proprietors. As chance furnished to me opportunities of seeing
the beds, or as small specimens of the marl were sent to me for
examination, I gradually came to know the greater extent of this
bed. It is now known at various points in an area of about twelve
miles in length, from east to west, and eight or ten miles wide,
which area takes in parts of the counties of Prince George (which
has much the larger known portion), Charles City, and the lower
point of Chesterfield. And in this area also is the broad bed of
James river, and the lower parts of its tributaries, Appomattox
river, and Bailey's, Powell's, and Herring creeks. The marl is
exposed to view on the southern side of James river, at the fol-
lowing several points : Coggins Point, Maycox (a mile below, and
the most eastern exposure as yet known), Tarbay, Wm. H. Harri-
son's farm, and Beaver Castle, all above on the river — Eelbank
and Hawksnest (the most southern exposure), on Powell's creek —
the Old Court House tract and Spring Garden farm, both on Bai-
ley's creek, and the latter from one to two miles above the head
of its tid^, and three miles south of the Appomattox where oppo-
site. The last is the most western exposure. On the northern
side of the Appomattox, it is seen in the river bank at Bermuda
Hundred, and north of James river, and of Herring creek, at
Neston and Evelynton.

Through nearly all this large area, this bed of marl preserves
remarkable uniformity of appearance, texture, chemical character
and composition, and even of the thickness of the stratum, and
of the succession and variations of character of the several smaller
layers of the general body. The bed lies nearly horizontal, but
dips slightly and irregularly eastward and northward. At Coggins
Point, its lower part is 10 to 12 feet above high tide, while at
Maycox, a mile to the east, and at Evelynton, three miles north, it
is lower than high tide mark. Yet not so much difference of ele-
vation as this is seen in all the greater extension westward to
Bermuda Hundred. The stratum varies from 4 to 10 feet thick,
being thinnest at its south-western exposure, Spring Garden,

EOCENE MARL. 453

and tlilckest at the north-eastern, Neston and Evelynton. At
Coggins Point, where traced along the face of the river cliff con-
tinuously for more than half a mile, it is usually 6 feet thick,
never more than 8, and never less than 4 feet, except where
terminating. The general and almost uniform colour is a pale
dingy yellow. The few shells remaining are not perceptible with-
out careful observation, and the whole mass, when dug down for
use, is scarcely distinguishable from many common and barren
sub-soils, or clay river cliffs, of like colour. Two thin but con-
tinuous and separate layers of almost stony hardness extend
through the whole bed. These contain from 85 to 90 per cent,
of carbonate of lime, and may be burnt to excellent quick-lime
for cement. The marl intervening with these hard layers is simi-
lar to them in colour and general appearance ; but is quite soft and
mellow in handling, and in that respect differs from all other known
marls. The very uniform calcareous proportion of this part is
about 53 per cent.; and taking an equal section of the whole
thickness of tlie bed, and with the greatest care to obtain a fair
average sample, the strength in carbonate of lime was found to be
62 per cent. This is far less of calcareous matter than is con-
tained by many miocene marls which show less effect than this as
manure. But besides its calcareous matter, this eocene marl has
some little gypsum, some kind of saline matter which cattle are
fond of licking (believed to be sulphate of alumina) and some
amount of the granules of " green-sand" — and more of this than
most of -the miocene marls. The other earth of this marl is mostly
of yellowish clay, and composed more of argillaceous than sili-
cious matter. I confess that all these additional ingredients, toge-
gether, do not seem to me sufl&cient to account for the superiority
which this marl exhibits as manure.

Though this peculiar kind of marl was so early known, and its
value appreciated, and, though it underlies the whole of Coggins
Point, yet it is covered there so deeply by the overlying earth, and
is therefore so difficult to work extensively, and, moreover, is so
distant from the main body of the farm, that this has not been
applied to more than 65 acres, out of some 700 marled on that
farm. Other proprietors have elsewhere made much more extensive
applications of this marl. The peculiar effects of this kind of marl
were tested with the most accuracy by Messrs. Collier H. Minge,
then of Walnut Hill, and Hill Carter, of Shirley ; both of whom
used this marl from Coggins Point, water-borne to distances of
twelve and fifteen miles. Though the marl was given to them (iu
the bed), it was yet very costly in the labour of digging and trans-
portation; and therefore they used it with strict economy, and
carefully estimated the results. But highly as they both thought

454 EOCENE MARL.

of, and have reported the effects,* in comparison with either lime
or miocene marls, the expense and trouble were so great, that it is
now considered by some of the most judicious farmers on the tide-
water rivers, that they can better afford to buy stone-lime, at its
present low price (8 to 10 cents the bushel), than to transport
marl of any kind by water. This, however, is an erroneous esti-
mate. A bushel of such marl is worth more as manure, than a
bushel of slaked lime (though slower in operation), and can be
transported twenty to forty miles by water, and delivered for 4
cents the bushel.

Since the foregoing pages were written, I have learned of two
farther exposures of this body of eocene marl. One is four miles
north of Evelynton (in Charles City county), where the marl was
reached and penetrated by the digging of a well in 1814. At
about thirty feet deep, after passing through the marl, and a layer
of rock, water was reached, which rose to the top of the well, and
continues to flow over, forming the only Artesian well known in
this region. The other locality is in Henrico county, on Turkey
Island creek, its eastern boundary, and about eight miles north of
City Point. This marl I recognised to be the same, by a specimen
recently brought me for examination. It is below the surface of
swampy ground, and is coloured dark gray. It is much fuller of
green-sand, and indeed in that respect makes some approach to the
green-sand marls of the Pamunkey, of which the nearest exposure
is only sixteen miles from this place. It is probable that the marl
extends continuously from the one place to the other, and may be
found throughout the interval by deep digging.f

(e) The Gypseous Earth or Green Earth of James River.

Before proceeding to consider the next and only remaining
known variety of our marls, the eocene green-sand marl, it is ne-

* See Fanners' Register, vol. v., pp. 189, 247, 511.

f After the publication of this report, I first learned, from the examina-
tion of hand specimens, that eocene marl was exposed on the new railway
route between Fredericksburg and the Potomac river. The specimens ex-
hibited to me were very hard, and seemed (to the eye) to be also poor.

The most extensive, rich, and valuable body of marl, of the Atlantic
States, is eocene, and which I first knew, and then examined extensively,
during ray Agricultural Survey of South Carolina, in 1843. This im-
mense body extends across lower South Carolina, and also the connected
parts of both North Carolina and Georgia. The bed is full 300 feet thick
under Charleston, and of unknown depth elsewhere. It contains usually
from 65 to 90 per cent, of cai'bonate of lime — has but few whole or distin-
guishable fragments of shells remaining — and is of more homogeneous
appearance and firm or stony texture than any other beds of marl.

GYPSEOUS EARTH OP JAMES RIVER. 455

cessary to treat in advance and separately of tlie peculiar earthy
compound, called " green-sand" by geological writers, of which the
large admixture, and sometimes even larger proportion, or other-
wise some other ingredient usually accompanying the green-sand,
gives additional value and peculiar character and action to th'e greater
number and quantity of the eocene marls yet known in Virginia,
But important and valuable as may be the green-sand in itself, and
necessary to be considered in connexion with the subject of eocene
marl, with which it is so inseparably connected, I wish especially to
avoid confounding the two earths under one name or one character ;
and to be understood as protesting against the prevalent error, in
giving currency to which scientific writers have concurred with the
unlearned cultivators, of applying to the non-calcareous green-sand
earth the name of " marl,'' and thus adding another, and the most
important, to the many previous misapplications of this wonderfully
misused and misunderstood term. This misapplication is universal
in New Jersey, where the green-sand earth is most abundant, and
is generally very rich in its distinguishing ingredient (usually con-
taining 75 to 90 per cent, of pure green-sand), and where this earth
has been long and is now extensively used as a manure, and has
been found to be of great value as a fertilizer. I shall hereafter
refer to both the points of resemblance and of difference (both of
which are important and interesting,) between this green earth of
New Jersey and that of James river ; but, for the present, my re-
marks will be confined to the latter, and its use as manure, as
known principally, and indeed almost entirely, from my own ob-
servations and practical experience, there having as yet been but
few trials of it made by other persons.

It was mentioned in the foregoing section, that the first notice or
observation of the eocene marl, on James river, was induced by the
previous discovery and examination of the green or gypseous earth
— the latter being the universal underlying bed of the former, and
connected with it in more respects than merely its subjacent posi-
tion. It was my chance, or the result of habits of observation of
marls and other earths, and not of any scientific knowledge or pre-
vious preparation for such investigations, which led me, in 1817, to
be the first to observe this bed of green earth in the river banks of
Evergreen and Coggins Point, and to trace it where visible along
the intermediate ground, a distance of about eight miles. Since
then, it is known to be much more extended ; for it not only under-
lies all the eocene marl of the same neighbourhood, wherever that is
found, and part of the yellow sandy miocene, but also extends be-
yond, and is found at various places where no eocene or even mio-
cene marl is present. The most western limit, seen after a long in-
terval, or concealed existence of this formation, is at Petersburg,
where it shows in the ravines south of Poplar Lawn,

456 GYPSEOUS EARTH OF JAMES RIVER.

What first directed my attention to this earth was the existence
in the river bank at Evergreen (the place of my birth, and of resi-
dence in early life,) of curiously shaped and beautiful crystals,
which subsequently I learned were selenite or gypsum. The like
crystals (though much smaller in size) I soon after found in differ-
ent places at Coggins Point, my own farm and then residence. And,
in making examinations for this purpose, I observed that wherever
any gypsum could be found, it was always in a peculiar kind of
earth, which, though varying much in appearance in different places,
and at different elevations at the same place, yet possessed charac-
teristic marks by which it could be easily distinguished from all
others. This was the earth in question. For want of any known
or more appropriate name, I at first applied the term " gypseous
earth'^ to this deposit ; and though I subsequently abandoned this
name in (undeserved) deference to scientific authority, and have
used instead, in my later publications, the name " greei-i-sand earth,''
I now believe that my original term (in reference to the more gene-
ral and universal manuring qualities) was the better of the two, for
reasons which will appear in the course of these remarks. And
besides that " green-sand earth" is inconvenient for its length, it is
not truly descriptive ; for the entire granules from which the pe-
culiar character of the earth is derived, are not green, but black
superficially, or so appear ; and are not what is usually understood
as sand, but in texture are like fine and unctuous clay. Still worse
is it to term the whole mass " green-sand," as is usually done when
the pure "green-sand," even if that were properly named, may not
form one-fourth or even one-tenth of the whole mass of earth. I
therefore would prefer for the deposit, and shall use indifferently,
either my first designation of gypseous earth, or the name of green
earth, which latter is convenient, is sufficiently descriptive, and,
moreover, affirms nothing except as to the colour, which is generally
manifest in the whole mass, and, if not, is certainly so in the sepa-
rated and mashed granules, which distinguish the earth.

As the lower part of the river bank is mostly exposed and kept
bare by the frequent washing by the waves driven by strong winds
and high tides, the bed of gypseous earth can be easily traced
through nearly its whole course along the river side. As thus ex-
posed to view, it has generally a green colour, most frequently in-
termixed and mottled with smaller streaks and spots of bright yel-
low. The earth, as seen firm in the bank, and with a smooth waslir
ed surface, might be supposed to be somewhat of a clay; but, on
handling it, and breaking down a lump, its texture is more like
sand ; as indeed the larger proportion of the mass is silicious sand.
A very general distinguishing mark of this earth is its containing
numerous hollow impressions of eocene shells, of which the forms

GYPSEOUS EARTH.' 46t

remain perfect, thougli neither the shells themselves nor any portion
of their calcareous substance remain, as the earth in this part, and
where most generally seen, contains not a particle of carbonate of
lime. Among the yellow spots there are also other small spots and
streaks of reddish brown-coloured clay, very pure, soft and unctuous
to the touch. The bright yellow clay is doubtless largely impreg-
nated with iron, or is a true ochre. Though soft within the bed,
this yellow ochre hardens when exposed to the air on the outside,
and even when under water. Many of the yellow spots made by
this ochre, as seen on the surface of a smooth section of the bed,
have a faint resemblance to the shape of sections of bivalve shells ;
and these contrasted with -the general green ground, and with the
exception of the colours being different, give to such a section of
the bank somewhat the appearance of the beautiful black marble
used sometimes for mantel-pieces, in which the white traces of what
were formerly shells show throughout. In some places near to and
below the beach, the earth is seen much darker coloured, indeed is
almost black when moist in the bank, though more of dark and
dull green when dry. This deeper colour is owing to the green
granules being present in larger quantity ; and generally, if not
always, the lower part of the bed of earth is richer in that ingre-
dient than the upper. The empty impressions which were former-
ly filled by shells are still found in penetrating below ; but as the
depth increases, first are seen some fragments, and then whole shells,
though greatly decayed, and the parts having scarcely any coherence.
Still, generally, even below, where these shells are most abundant,
their quantity would not furnish as much as two per cent., and gene-
rally not one per cent., to the whole thickness of the bed; and,
therefore, the carbonate of lime, though of course useful in pro-
portion to its quantity, can give no appreciable addition of value
to the mass as manure.

Here and there, but rarely, in the upper and dry part of this bed,
crystals of gypsum are found, generally so small as to be barely
distinguishable by the eye. In the lower and wet part, gypsum is
never visible ; but it is nevertheless believed to be always present
in some proportion.

But the important and most characteristic mark of the green
earth is present in the black granules called " green-sand," which
give colour to the mass. To ascertain the presence of these gra-
nules, let a small sample of the earth or marl supposed to contain
them be dried, and then crumbled between the fingers, or, if too
hard for that, by being rubbed in a mortar, not too finely and closely.
Then take a pinch of the powder between the thumb and finger, and
sprinkle it very thinly over a piece of white paper. If any of the
separated grains appear black (or green), mash one of them with
39

458 GREEN-SAND.

the moistened point of a pen-knife; and if it be " green-sand/' the
granule will mash like fine soapy clay, and make a vivid green
smear.

For greater accuracy^ let the earth (or marl) be well washed by
agitation in water, and pour off the pure clay and other lighter mat-
ters which will remain longer suspended in the fluid. The grains
of green-sand will then be left with nothing else but the qiiartz or
silicious sand, and moreover the former will be made more percepti-
ble, in consequence of being cleared by the washing of any previous
covering of fine clay.

My first published account of this earth was made in or about
the year 1828, in the old series of the /^American Farmer/'- A
much more extended article " On the Gypseous Earth of James
E-iver,'' I afterwards published, July, 1833, in the first volume of
the Farmers' Register, beginning at page 207. Though up to that
time I had never so much as heard of the term ''green-sand,^' and
though I adopted and used the new and unauthorized designation
of "gypseous earth,'' the earth inquestion was described so minutely
and accurately that it was impossible for any intelligent and atten-
tive reader of the article, and subsequent observer of the kind of
earth in question, to mistake the subject of description. In this
piece I also asserted the identity of this gypseous earth with the
" green marl" of New Jersey. I trust that I may be pardoned for
thus specifying my claim to the first discovery of this earth in Vir-
ginia^ inasmuch as that merit (if it be one) would be ascribed by
every otherwise uninformed reader of the first report of the geolo-
gical survey of Virginia, and some other of the publications from
the same source, to the author of these pieces.* Upon this occasion^
it would be improper to say more on this question than thus con-
cisely and explicitly to assert my just rights.

Before proceeding to offer the more precise and more valuable
information concerning this earth obtained by very recent investi-
gations, it will be propey to state something of the progress and
changes of opinion on this subject, which operated at different
times either to encourage or to obstruct the use of this earth as
manure.

From 1818 to 1835 inclusive, I made numerous trials, and in
some cases extensive applications of the Coggins Point gypseous
earth as manure. The results of my general practice, and also of
many particular experiments, noted at the times when made, were
reported in a communication to the Farmers' llegister, commencing
at page 118, vol. ix. The effects stated were very different and
apparently contradictory — sometimes beneficial and profitable in a
remarkable degree, but more generally of little value, or of no

* Professor W. B. Rogers, formerly Geological Surveyor of Virginia.

GYPSEOUS EARTH. ~ 469

"benefit whatever. The inferences which I drew from all my expe-
rience (and there existed scarcely any other known facts or experi-
ments), were that this earth as manure acted in the same manner
as gypsum, though more powerfully — and in no other manner than
as gypsum would under like circumstances ; that like gypsum, ou
my land certainly, and as I inferred in our tide-water region gene-
rally, this earth had no effect whatever on any acid soils — and rarely
on any other crop than clover (and other leguminous plants), even
when properly applied on neutral or calcareous soils ; and that when
naturally acid soils were made calcareous by being marled, this
green earth then became generally operative thereon as a manure
for clover (and for other plants of the clover or pea tribe), in the
same manner as is usual in regard to gypsum.* And though the
effects, when any were produced, were greater than those of any
usual or known dressings of gypsum, and sometimes in a very re-
markable degree, still the failures and disappointments were so many
that I did not deem the practice worth being continued. In 1841,
my son, the present occupant of the Coggins Point farm, at my
request, recommenced the applications of gypseous earth, for ex-
periment; and on the clover of this year, 1842, he has extended
the dressings over more than 60 acres. f The results were, as in
former years, very unequal, and for the greater space of ground
covered, unprofitable, and barely if at all perceptible. But on 25'
to 30 acres the benefit was remarkably great, and in some cases (of
summer dressings) improvement was obvious within ten days after
the application. But what was most interesting in the results was,
that a clue seemed to be thereby furnished to explain the frequent
previous failures of this manure, even when applied to clover grow-
ing on neutral or calcareous soil, which are the only circumstances
in which it has ever been found profitable in practice. My former
applications had been generally made from the upper and greener
stratum of the gypseous earth (designated in a succeeding page as
(7), or if from the lower and blacker part (i7), the digging did not
penetrate more than a foot, or, at most and rarely, two feet below
the before exposed outer surface. But in the recent larger opera-
tion, the digging (made on the river beach) was so much more ex-
tensive, as to furnish earth from depths of three or four feet, as well
as of portions nearer to and at the surface. I ascribed the remarka-
ble differences of effect to the kind and place of the earth ; inferring
that the exposed parts, and all perhaps near the surface, had, by
exposure to air or water, lost a large proportion of the soluble or

* See these views more fully set forth in the article above referred to,
and also in another on the green-sand marls of Pamunkey, at pp. 679 and
690, vol. viii. Farmers' Register,

■f See the facts and results stated in two communications to Farmers'
Register, pp. 86, 135 and 252, vol. x.

460 GYPSEOUS EARTH.

decomposable fertilizing ingredients. As the applications had not
been made with any view to this question, the experiments are not
to be deemed as conclusive, and the correctness of this inference is
yet to be fairly tested by future experiments.* But the benefits
from some of the dressings, and all of those supposed to be from
the deeper digging, were so great, and so speedily produced, that
renewed and strong interest was excited in regard to this manure.
The quantity applied was geuerally 40 bushels of the earth to the
acre. And this quantity seemed (from an accurate comparative
experiment) to produce as much benefit as 200 bushels. The
growth of clover was increased in degrees varying from 100 to 300
per cent. And where the application was most successful, the in-
crease and profit were sufficient to compensate the expense, even
though no further benefit shall be found than in this one crop — or
that a new application shall be required, and be made, for every
succeeding crop of clover, or once in each round of the rotation of
crops.

An observation made by accident last spring led to further
chemical as well as other examinations of this earth, and to im-
portant results. Upon heating a lump of it to red heat, I found
that strong fumes were thereby extricated, which were almost suf-
focating if inhaled incautiously. The odour was manifestly sul-
phureous in part, and principally ; but it seemed not altogether so,
but to be mixed with some other, much like that of muriatic acid
gas. Similar trials were made on many specimens, and all the
darker and (as supposed) richer layers of the green earth at Cog-
gins Point showed the like result. From specimens of the upper
and lighter green stratum ( C) when heated red, there was nothing
of this suffocating odour produced. And it may be useful to state
here, in anticipation of subjects to be hereafter more fully consi-
dered, that I subsequently found that the New Jersey green-sand
earths yielded not a particle of this gaseous product.

This odour, so far as it was sulphureous, was obviously the pro-
duct of the decomposition (by red heat) of sulphuret [or bi-sulphu-
ret] of iron — which was thus proved. to be universally diffused,
though invisible, through all the darker and better kinds of this
earth. Sulphur would have shown like results, with a much les-s
degree of heat ; but it could not be that, because the heat sufficient
to decompose sulphur (and to evolve its fumes) had no such effect
on the earth. I also observed that lumps of the earth, after having
been applied as manure, and exposed on the surface of the ground
for some months, often had a smell of sulphur; and, in some cases,

* Subsequent experiments have not sustained the above idea. But the
results, though not uniform, have been so generally beneficial on clover,
that this earth is applied to from 60 to 80 acres every year.

GYPSEOUS EARTH. 461

the same effect was exbibited in specimens taken from tlie diggings,
and kept dry. The sulphuret of iron, if universally present, would,
by its decomposition in contact with carbonate of lime (as when on
calcareous land), form sulphate of lime (gypsum). This showed a
source for the universal supply of that manure to some extent.
Further, my friend Mr. M. Tuomey,* had found sulphate of lime
ready formed in specimens of wet earth, which I supposed the least
likely to retain that ingredient — and thus was indicated another and
more general supply of gypsum already formed.

The increased interest excited by these new observations, and
also the new views as to the cause of the failures of most of the
former applications of this manure, induced the sinking of a pit in
the gypseous earth, on the river beach at Coggins Point, to the
depth of 18 feet below ordinary high tide. This digging for the
lower 13 feet was in a very compact and fine clay (^), or clay marl,
as it would have been designated in England, from its texture and
sensible qualities, but which contained no visible or apparent fer-
tilizing ingredient, except a very small sprinkling of shells, and
elsewhere some little sulphuret of iron in small lumps and in minute
crystals, visible in a few detached spots only. The appearances
promised so little of value or remuneration (and less so as the dig-
ging was sunk lower), that the work was suspended. But the
blacker earth above (i>) and also the clay (^E) were carried out for
experiment on clover (May 26th), of which the first crop had just
been grazed off closely, and the cattle removed. As the season was
so far advanced, and benefit so little counted on, the covering was
made heavier than in the winter and early spring before (and of
which the full benefit had been already seen on the first or spring
crop of clover) ; 100 bushels of the upper and better earth, or 150
of the clay, being applied to the acre. A good rain fell the next
night; and in less than ten days there were visible and manifest
beneficial effects from both kinds of earth, but better from the upper
— which effects increased to fully the doubling of the growth by the
1st of August. The hard lumps of the compact clay soon split
and crumbled when exposed to the air, and even without rain. The
remarkable benefits of these applications induced the resuming of
the digging, and another and much deeper pit was dug as early as
the other labours of the farm permitted, and a statement will pre-
sently be made of the section thereby exposed. But previous to
this, it is proper to describe another like operation, and its results,
at a more interesting locality.

The same general appearance of the gypseous earth, and mostly
of the poorer kind of greenish colour, mottled with pale yellow clay,

* Now Professor of Geology and Agricultural Chemistry in the Univer-
eity of Alabama.

39*

462 ' GYPSEOUS EARTH AT EVERGREEN.

is exhibited all along the river bank of Coggins Point and the lands
above, to the Evergreen farm — interrupted only by the parts of
marshy or more ancient alluvial lands ; or where the stratum has
been broken and concealed by the ancient land-slips which have
greatly altered the original levels and form of the surface of that
whole stretch of land bordering on the river and overlying the
gypseous earth formation. This operation by the land slipping and
sinking continues^ and some new effects are seen every year. At
many places along this stretch, gypsum is perceptible in the green
earth, either in crystals or in powder, and sometimes, and rarely, in
considerable proportion, say from 5 to 15 per cent, of the whole
mass for very limited spaces. At the upper part of the river line
of the Evergreen farm (at the mouth of Bayley's creek, and two
miles below City Point), the river bank has peculiar and remarkable
features, which deserve particular notice. It was here, in 1817, that
I first discovered this green earth formation, and thence traced it to
my own farm and then residence, Coggins Point, and elsewhere in
that neighbourhood.

The lower visible part of the body of gypseous earth at Ever-
green is laid bare by the wasting encroachment of the river (by
which it is rapidly washing away), for 200 yards in length. The
southern or upper extremity, for some 20 yards, approaches nearly
in appearance to the general character of the upper stratum before
described. But all the remainder is different, and much richer in
the dark or green granules than generally elsewhere.

Since this article was commenced, Capt. H. H. Cocke, the pre-
sent proprietor of Evergreen, at my suggestion and request, had a
shaft dug for examination, which, with an extension of my own after
he had ceased his operations, added to the natural and higher ex-
posure of the section, 27 feet below the beach, and 25 below com-
mon high tide. The several strata of the whole section, and their
variations, will be described in their descending order.

At top —
1st. Surface soil ^sloping back irregularly to the table land, which
is much highei-), on (2d) gravelly and sandy sub-soil, pervious to
water, of various depths — lying on strata nearly all horizontal.
Next,
10 feet of yellow sandy miocene marl.
8 feet of yellowish clay (supposed eocene), intermixed throughout
with very small crystals and powder of sulphate of lime — the clay
not compact or solid, but open and loose throughout. (Query : Is
not this the equivalent of the eocene marl at Coggins Point,
with its former shells and carbonate of lime completely changed
to sulphate of lime, and the greatest proportion dissolved and
lost?)
6 feet of gypseous earth — the general colour; green mottled and

THE DIFFERENT LAYERS. 463

streaked with yellow oclire, and full throiigtiout of very minute
crystals of sulphate of lime, supposed by the eye to be about 10
to 15 per cent, of the whole mass. No shells or casts seen in
the part exposed by digging for examination.

7 feet of brownish mottled clay, feeling smooth and soapy, con-
taining numerous small crystals of sulphate of lime.

9 feet very pure white clay or fuller's-earth, in horizontal layers,
separated by veins of the yellow clay (or iron ochre) before-
mentioned, other veins of the same sometimes also inclined and
crossing the horizontal veins — the outsides of the lumps of clay
coloured by oxide of iron. The clay all broken into irregular
lumps, as if the fissures had been formed by the contraction in
drying of clay soft and distended with wetness. No shells, nor
appearance of them, but many pure and transparent and beauti-
ful crystals of sulphate of lime here and there, some weighing
several ounces. This stratum changing gradually into the next of

4 feet of dark bluish clay, the colouring matter being green-sand,
mottled with irregular streaks of bright yellow, becoming brown
below where oozing water begins to show and is reddish with
sulphate of iron, or other ferruginous matter in solution. This
stratum full of large and solid crystals of sulphate of lime,
amounting apparently to from 20 to 25 per cent, of the whole
mass — the crystals coloured dark gray, because of some impu-
rities in small grains (green-sand ?) being enclosed and diifused
through them. No shells. This changing into the next, of

11 feet of same dark or nearly black clay, nearly uniform colour,
and still compact texture, and feeling smooth and soapy — with
very few crystals, and much less sulphate of lime than the pre-
ceding, but many small and scattered eocene white shells, quite
rotten, and being moist, as soft as dough. The shells, mostly
several kinds of very large turritellge. Fewer shells as descend-
ing. At top of the stratum some large and very perfect speci-
mens of the ostrea compressirostra (f) To level of the river at
common high tide.
Below high tide.

14 feet very similar to the last, the shells very few for the greater
part, but increasing near the next. No crystals or other sulphate
of lime visible. The green-sand granules coarser — sometimes
in small lumps quite pure, or unmixed with anything else.
These granules breaking easily, though as if hard or brittle, and
not like a soft soapy clay as usual — though as green as before.
Many small cylindrical tubes seen (made by the burrowing of
pholades, or other shell-fish of the like habits), which seem to
be formed on, or coated with pure green-sand in Aiass, and green
in colour, and the hollows filled with looser black granules.

11 feet of shells lying generally close together, and serving -to

4fi GYPSEOUS EARTH AT EVERGREEN.

make tlie whole stratum a calcareous marl, of perhaps SO per
cent, or more of carbonate of lime — the earth filling the shells
and between them being the same black earth, as rich as before
in green-sand. At top, some very large and perfect shells of
ostrea compressirostra, and another much thicker ostrea, not
known.* The shells mostly very large turritellce of different
species — near bottom fewer of these, and mostly crassatellcR.
The shells nearly as numerous as before, at this depth, at which
the digging was abandoned, at 25 feet below tide.

The whole section, from the top of the highest undoubted
eocene stratum to where the digging ceased (without any indica-
tion of being near the end), is 61 feet — and if the clay and gyp-
sum stratum below the miocene be added, which, though not cer-
tain, I believe to be eocene, there would be 69 feet. And if this
and the two other lower clay strata be deducted, there will still re-
main 45 feet of strata exposed, all rich in green-sand, and of it 9
feet very rich also in sulphate of lime or gypsum, and 11 feet mode-
rately rich in carbonate of lime. 8ueh a deposit is well worth the
examination of geologists and chemists, and the trial of farmers.*)*

It was remarkable that at this place only of all the usual strata
of all the then known deposits of green-sand or eocene marl in
Yirginia, were found exposed, the shells of the ostrea compressi-
Tostra — and below tide the other before unknown and very thick
and heavy ostrea ; J and that at this place there has not been found
a single shell of either the ostrea sellceformis or cardita plain-
costaj the latter of which is so abundant through all other known
eocene deposits, and the former in the calcareous eocene else-
where. These facts seemed to indicate (as well as the general
dip to the eastward) that the strata at Evergreen are much more
elevated than the same at Coggins Point — and that by digging
deeper, the lower and all the strata of the former might be found

* One of these last (both valves) weighed 5 lbs. Mr. M. Tuomey, to
whose much better information on this subject I ought- to defer, supposes
this very large and heavy shell to be an 0. compressirostra of unusual age
and growth. If so, however, it is certainly very different in appearance
from that shell, as usually seen higher up in this bed, even when wider
than this very thick and heavy ostrea.

[f The lowest known layer of this rich deposit has since been traced
three miles westward to City Point; and from the latter place the marl has
been used extensively, and to much benefit. 1851.]

X This last shell I have since learned (by specimen) is also found in
the green-sand marl at North Wales, near the upper termination of the
Pamunkey bed — and near the bottom of the marl. And later personal in-
spection has sho|rn clearly the identity of the deposits and the fossils at
tliese two points ; one being the bottom of the Pamunkey bed, and tlie
other nearly (as is presumed) to the bottom of the James river bed of
green-sand marl.

GYPSEOUS EARTH AT COGGINS POINT. 465

at other parts of the known area (before described) of the eocene
formation.

This inference added to other considerations caused to be sunk
the second shaft above-mentioned in the beach of Coggins' Point,
130 yards distant from the first one, which by this time had been
filled completely by the sand driven by storms and high tides. The
digging was made at a low part of the bank, and which therefore
did not show either the eocene marl or the miocene, the former of
which is seen in the higher bank at a short distance, and both
together at the distance of a mile. The diiTerent strata of the
actual section at the new digging, taken descending from the top
of the bank, were as follows : —

1 foot, sufface soil — gray loam.

7 feet of (drift) pale yellow clay, containing much coarse silicious

sand.
4 feet (drift) rounded or water-worn pebbles, of all sizes, from 4

inches through to coarse gravel, held together by enough clay

and ferruginous earth to fill the interstices between the pebbles.

None of the pebbles calcareous.

2 feet of (drift) very thin layers of hard and gritty gray clay,
alternating with others of coarse ferruginous sand.

2 feet of poor greenish earth, more than half the surface of the
section brown in spots, and indurated with oxide of iron.
(Here should be, as elsewhere in the neighbourhood, though

absent at this particular locality, either one or both, the miocene

marl (J.), and next below the eocene calcareous marl (i>) described

in the preceding pages).

(6^) 9 feet of the ordinary upper layer of gypseous earth — green
colour, mottled with spots of bright yellow clay (or ochre), and
some other spots of unctuous reddish brown clay. Very slight
efiiorescence of gypsum on the surface.

(D) 3 feet of darker and nearly uniform colour, almost black, from
the greater proportion of green-sand. This and the preceding,
containing many impressions of shells, but no shells or frag-
ments, and no carbonate of lime. More eflSlorescence of gypsum,
and also on next —

(X>) 3 feet of same, except that some shells are seen — and increase
in the next to level of river at common high tide.

(i>) 6 feet of same (next below tide) — the shells mostly cardita
planicosta — fewer of cytlierea and corhula. No ostrea or turri-
tella. Small and slender shark's teeth (so called) in perfect
preservation, the points and edges being as sharp as in teeth of
the living animal.

(£") 15 feet bluish gray or lead-coloured clay (from G to 22 feet
below tide), having nearly the texture of clay marl. Very com-
pact and firm in texture — unctuous to the touch, but not adhe-

46o l)IFi'ERENT LAYERS OF THE BEli:

sive or tougli — does not bend to pressure, but breaks — cuts
smooth, except when the edge of the knife meets parts of shells,
or grains of silicious sand, which, as well as granules of green-
sand, are irregularly intermixed throughout. The shells very
rotten, and flattened by pressure. Sometimes in masses, or thin
bands or regular layers, becoming less and less in quantity as
descending, and but few seen at and below 10 feet of this stra-
tum. Numerous particles of mica throughout. Changing gra-
dually to next. At 12 to 13 feet of its depth, many hard lumps
of. sulphuret of iron. The upper three or four feet of this
penetrated by numerous hollow cylinders, of an inch or more in
diameter, and in every direction — obviously having been bored
by shell-fish. These hollows are filled by the green dkrth of the
stratum above, which thus makes nearly half the mass. (This
clay and the layer above (D) were the kinds used for manure
from the first opened pit.)

3 feet (22 to 25 below tide) of brownish and more friable clay, in-
termixing at first with the above. Green-sand much more
abundant than in the preceding, and partly in very large granules.

3 J feet (25 to 28 below tide) af very smooth and firm clay, of
delicate lilac colour at first, but becoming paler as descending,
■until nearly white. Splits easily into flakes like thick slate ; and
still thinner laminae show that the earth was a deposit in tranquil
waters. Thin flakes (not thicker than writing paper), and some-
times a mere powder of pure sulphuret of iron visible between
many of the layers of clay, and causing them to separate easily.
The upper foot of this penetrated everywhere by small hollow
tubes (from an eighth to the third of an inch in diameter), which
are filled by the brown and green variegated earth of the stratum
above — causing a lump when cut smooth to appear like a con-
glomerate of difi'erently coloured marbles. Except in these bor-
ings, no green-sand deposit, and no shelly matter. The sulphuret
of iron, which is through this stratum visible in powder, or thin
layers, and above in small masses or lumps, is diffused through
all the strata containing green-sand, except the highest ((7).
Through this and the upper gray clay (^) some small black
pebbles seen, which appear as if formed by melting. The same
found in the eocene marl. A sudden change to the next —

2 J feet (281 to 31 below high tide) of remarkably smooth and
unctuous, but firm clay of reddish brown colour (or dull brick
red), and homogeneous texture as well as colour. Cuts as smooth
as the best hard soap. Deposited in thin laminae, and breaks or
splits easily in straight lines both in the direction of the laminaj
and lengthwise at right-angles to their direction — the grain and
fracture appearing like that of rotten wood. Across these two
directions; the fracture very uneven. Near the bottom of the

THE DirFERENT LAYERS. 4G7

richesfc green stratum (7>) there is a barely perceptible oozing
of water. All below dry, and the two last strata remarkably
dry. They could not be more so if within three feet of the
surface of a high knoll, and in summer.
1 foot (31 to 32 below tide) of same as the last in texture, but of

pale blue colour.
1 foot (32 to 33 below tide) mixture of the last, in small lumps
imbedded in the next, as if broken up by a violent current, and
deposited in rapid water.
17 feet (33 to 49 below tide, the lowest digging) black earth —
richest in green-sand (supposed to be 40 per cent.) mixed with a
few fragments (less than 2 per cent, on an average) of shells,
mostly small, and all very rotten. Kinds, mostly of turritella
(some of which are large), mytylus, corhula, and crassatella.
Many small and a few large shells of ostrea comj^ressirosfra near
the top of this stratum and again near the lowest part, where
the work was stopped by the water rising from below.
The whole, so far as dug, added to the before exposed bank,
amounted to 66 feet of the eocene deposit, of which 49 feet was
below the level of high tide. The last stratum, which was pene-
trated for 17 feet before the rise of spring water compelled the work
to be discontinued, was manifestly the same with that at Evergreen
which was even with high tide (and extending above and below),
and which was there 25 feet thick. It was a subject of much re-
gret, after so much labour, that the still lower stratum, full of shells,
could not be reached, and which probably might have been done in
8 feet more of digging. However, enough was done to show that
the quantity is inexhaustible of the layers richest in green-sand
(whatever may be that degree of richness), independent of the
other layers.

Besides the main object of this laborious examination by digging
as low as possible, to learn more of the quality and quantity of the
earth for manure, and as a matter of curiosity, there was another
inducement. The whole bottom of the river across to Berkley
(below the thin covering of loose and soft mud), according to its
variation of depth, must be formed of one or another of the same
layers shown in this digging of 49 feet below the water level ; and,
of course, Harrison's Bar, which lies between the Coggins and
Berkley shores, must be so formed. No earth more strongly re-
sists the washing action of water than the gypseous earth, even
when the least mixed with clay. This peculiar quality must bo
the cause of the existence of this bar, which presents so serious an
obstacle to the navigation of the river ; and it may be thence in-
ferred what would be the degree of dijQ&culty of its removal, and
also that the removal, if effected, would be permanent.
Various and contradictory as had been many of the results of

468. GREEN-SAND Or NEW JERSEY.

my experiments of the green earth as manure, there had been per-
fect agreement in some respects. Thus, as before stated generally,
the earth has never been beneficial as manure on acid soil — but
rarely on corn, and never (directly) on wheat ; and (on proper soils)
generally and greatly beneficial on clover, and perhaps all plants
of the clover and pea tribe — and the efi"ects, when produced, have
never been permanent, nor even very durable. And the effects
shown in these points of agreement were nearly all the reverse of
those ascribed to the New Jersey green-sand. In regard to these
effects, in the absence of all certain and particular information to
be obtained otherwise, I found it necessary to seek information in
person. The results of my inquiries and personal examinations, in
general, showed that the green-sand (called marl) of New Jersey,
though agreeing in some respects with ours in action as manure, is
operative generally on the greater number of soils and on most
crops, and is also very durable in effect. On the other hand, much
larger quantities are applied there (usually 200 bushels, and some-
times 400, or more, to the acre) than I have done with ours ; and
something of the more general benefit and longer duration may
perhaps be owing to that circumstance.* Whether the green-sand
is indeed the principal, or a very important manuring agent, of the
James river earth, or whether the other ingredients may not be
Btill more active than its green-sand, is yet undecided. -j^

It is indeed strange that such doubts should exist at this late
day as to the manuring action and effect of this earth — and still
more so that the chemical composition and ingredients of the
earth should not have been long ago ascertained. Yet previous to
the recent imperfect application of tests above referred to, there
had been no known full or correct chemical analysis made of the
earth in question ; nor even any partial examination for and report
of -the ingredients, that was entitled to any respect for accuracy
and fidelity. For these reasons I engaged the services of Professor
C. U. Shepard, for the analyses of specimens which I selected from
the different strata of the earth, at Ooggins Point, exposed in re-
cent diggings, including several which had been tried as manure,
and had operated with remarkable power and benefit. His report
of the partial analyses, which has been received since the preceding
and subsequent portions of this article were written, will now be

* See report at length on the New Jersey green-sand, and its operation,
at page 418, vol. x., Farmers' llegister. This deposit is of secondary for-
mation, while that of Virginia is of the tertiary. This difference of age and
probably of the matei-ials of the formation would seem to indicate a diflFer-
ence of chemical constitution — as there certainly is of manuring operation.

f [I have lately heard that phosphate of lime had been discovered as an
ordinary accompaniment of the green-sand of New Jersey, in the clay
which is a regularly existing ingredient. I do not know what reliance may
be placed on this report. — 1851.]

GREEN-SAND. 469

presented. It enables me to furnisli more of wliat is valuable, be-
cause more certain than everything else I could offer, or than has
before been offered to the public on this subject — prominent as it
has been made in the reports of the geological survey of Virginia.

" New Haven, October 26, 1842.

"Dear Sir — The specimens of green-sand and accompanying earths have,
agreeably to your request, received my particular attention ; and I now
proceed to apprise you of the results at which I have arrived.

" Commencing with the mechanical analysis of the green-sand, I was not
a little surprised to find that the green particles, when cleared by washing
of a slight investment of clay, assumed the aspect of chlorite and green
earth, and more rarely of grains of serpentine and fine scales of mica. The
other ingredients of the earth were chiefly grains of quartz (some of which
were penetrated by chlorite), and more rarely specks of garnet, iron pyiites,
and what appeared to be yellow phosphate of lime. Fragments of shells,
in a very decayed state, occur disseminated through the earth ; and I de-
tected also small teeth and bones of fishes. The proportions of the leading
ingredients are very difficult to establish with precision ; and after all my
examinations I can only give them approximatively, and within wide limits.
Thus, the quartz grains may be said to constitute from GO to 80 per cent,,
the chloritio and micaceous grains from 10 to 15 percent., and the fine clay
from 3 to 5 per cent.

' ' Nothing is plainer than that the green particles possess the character
here attributed to them ; since they put on all the properties so common to
chlorite, being sometimes in regular hexagonal plates, though usually in
little granules made up of impalpable grains, which under the pestle easily
separate, with an oily feel, into bright green specks. Subjected to acids
and heat, it agrees with true chlorite.

*' The existence of such a mineral in the present formation offers nothing
remarkable in a geological point of view, since it may have originated in
the decomposition of chlorite slate rocks, or of veins in primitive rocks (in
which chlorite often abounds), and in both cases iron pyrites is its common
attendant. Besides, it may have been derived from the metamorphosis of
pyroxene, or from amygdaloidal traps, a source of green earth very often
recognised in Europe and America. Indeed, chlorite (which is but another
name for green talc) is often interchanged for mica, as an ingredient of
primitive rocks, and is everywhere little prone to decomposition, being, on •
the whole, one of the most persistent of the simple minerals.

"Neither can it be objected that its chemical constitution is incompatible
with the results obtained for green earth ; for here we must bear in mind,
also, that it is impossible accurately to separate the green particles from
the mica, serpentine, and other ingredients with which they are associated.

"M. Berthier found the following composition in the green grains from
the green-sand of Havre (France) —

Silica 50.00

Protoxide of iron 21.00

Alumina . • 7.00

Potassa 10.00

Alumina 11.00

99.00*

" Mr. Seybert found in that of New Jersey —

* Geological Manual, by H. T. de fa Beche, Phila., 1832, p. 255.
40

«

470 ANALYSIS OP GREEN-SAND.

/

Silica 49.83

Alumina 6.00

Magnesia 1.83

Potassa 10.12

Water 9.80

Protoxide of iron 21.53

Loss 89

100.00*

"Prof. Wm. B. Rogers found in the green-sand of Virginian—

Silica 51.70

Protoxide of iron 25.20

Potassa 10.33

Water 10.

Magnesia, a trace

97.28t
" The foregoing may be taten as a fair exhibition of tlie composition of
the green particles in green-sand ; and the following analyses may serve to
show the constitution of such chlorites and mica as may be presumed to be
most analogous to the green substances in the earth under consideration.
M. Vauqaelin found in the green-earth of Verona —

Silica 52.00

Magnesia 6.00

Akimina 7.00

Protoxide of iron 28.00

Potassa 7.50

Water . . . . • 4.00

99.50t
"Dr. Thomson found in the chlorite-earth, from the highlands of Scot-
land—

Silica 48.1G6

Magnesia 2.916

Alumina 16.851

Oxide of iron . 19.000

^ Potassa '6.558

Lime 2.675

Water 2.350

98.718^,
" The composition of the most common silvery mica from Zinwald (Bohe-
mia) was ascertained by M. Klaproth to be the following —

Silica ^ 47.00

Alumina . 20.00

Potassa 14.50

Ox. iron 15.50

Ox. manganese 1.75

98.7511
Having described the grounds on which I arrive at the conclusion that

* American Journal of Science, vol. xvii., p. 277.
•j- Farmers' Register, vol. ii., p. 131.
X Shepards' Mineralogy, vol. ii., p. 225.
I Idem, ii., p. 225.
Jj Idem, ii., p. 41,

MODE OF ANALYSIS. 471

the gi;pen grains of this earth are chlorite, or chlorite blended with mica,
and rarely specks of serpentine, I cannot but express the opinion, that as a
mineral manure the efficacy of the green particles has been greatly over-
rated. As these particles are very little liable to decomposition, their ac-
tion, whatever it may be, must be slow, and, I should infer, nearly imper-
ceptible. Indeed, I am rather disposed to regard its favourable operation,
if indeed it has any, as flowing from a mechanical agency, after the man-
ner of a clay, than as arising from the liberation of its potassa through
chemical decomposition. Not that I would call in question the usefulness
of the earth taken as a whole, for happily this is too well established. But
when I find a decided content of sulphate of lime, with carbonate and phos-
phate of lime in addition thereto, together with distinct trjfces of organic
matter, it appears to me unnecessary to look any farther in order to account
for the phenomena in the case.

" I now proceed to state my method of examination, together with the re-
sults obtained.

" The specimens were kept in a dry room, exposed to air in shallow dishes,
for several weeks ; after which, portions free from crystals of sulphate of
lime visible by the naked eye, and large fragments of shells, were heated
in a platina capsule to 300°, Fah,, in order to expel hygrometric moisture,
and subsequently to low redness, to decompose organic matter,* The or-
ganic matter is very inconsiderable, and was in no instances rigidly de-
termined,

" Having ascertained by experiment that the iron-pyrites was not decom-
posable by tepid dilute hydrochloric acid, the following method was resorted
to for the determination of the phosphate of lime. Two hundred grains
of the triturated earth were suffered to stand (with occasional agitation) in
contact with a dilute hydrochloric acid for three hours. The whole was
then transferred to a filter, and the earth well washed thereon, with abund-
ance of tepid water. The clear fluid and washings thus obtained were
super-saturated with ammonia, and the precipitate subsequently digested
in a warm potassic solution for the removal of the silica and the alumina.
The per-oxide of iron and phosphate of lime now remaining, after being
well washed, were treated with a cold, dilute acetic acid, whereby the
pliosphate alone was taken into solution. It was then precipitated by
ammonia, dried, ignited, and weighed. Having found reason to believe
that the proportion of finely divided phosphate of linie was pretty uniform
in the different specimens of the green-sand, I was only at the pains to
determine its exact proportion in specimen No. l.f Having ascertained
how much per-oxide of iron each sample cohtained, this amount was de-
ducted from that yielded by the treatment of the same specimen with nitro-
hydrochloric acid (aided by gentle heat), whereby the sulphuret of iron
was decomposed. Thus the exact quantity of iron which was engaged by
the sulphur (and consequently the amount of bi-sulphuret of iron) was
ascertained.

" The carbonate of lime was determined in the usual way, viz., by treating
the first obtained solution in hydrochloric acid with ammonia, whereby the

* This last step was always attended with the extrication of a little sul-
phur.

f I will here observe that, by the process now described, it was ascer-
tained that had the whole of the precipitate by ammonia from the hydro-
chloric acid solution been taken for phosphate of lime, it would have in-
volved the error of an ovei'-estimate of the phosphate by nearly 800 per
cent.

472 ANALYSES OF GYPSEOUS EARTH.

silica, alumina, per-oxide of iron, and pliosphato of lime were tlirown,^lo-wn,
leaving the lime and magnesia alone in a state of suspension. The former
was precipitated by oxalate of ammonia, and subsequently the latter by
phosphoric acid.

'* The sulphate of lime was ascertained by boiling a determinate quantity
of the green-sand in water until the whole of this salt present was taken
into solution. The clear solution was treated with chloride of barium, and
the sulphate of baryta ignited and weighed. The sulphuric acid present in
the earth was thus arrived at, and, by subsequent calculation, the sulphate
of lime originally present was ascertained.

•'Sulphate of alumina (but no sulphate of iron) was found to exist, in
traces, by the precipitation of alumina, occasioned on the treatment of
the water boiled on the earth with ammonia. But in each case it was too
inconsiderable for the determination of its proportion. Chloride of calcium
(muriate of lime) was ascertained by treating the same fluid with nitrate
of silver. Its proportion did not exceed that in which it exists also in
common soils.

" Results obtained on sjpecimens of green-sand earth from Coggins Point, James

river.

** 'No. 1. From 8 inches within the exposed side of a ravine, where a
stream flowed by, and 15 feet from the top of the green earth.'* [Mid-
dle part of stratum Z>, see page 465.]

Hygrometric moisture (lost at 300°) . . . 6.50
By heating to low redness, it lost in addition 2.03

Phosphate of lime 0.25

Carbonate of magnesia, in decided traces.
Sulphate of alumina, in traces.
" *No. 3. Same as number 1, except from a deeper excavation.'
Hygrometric moisture (lost at 300°) . . . 4.600
By heating to low redness, it lost in addition 2.200

Carbonate of lime 1.550

Bi-sulphuret of iron 3.0G6

Carbonate of magnesia and sulphate of alumina in traces.
Phosphate of lime, about as in number 1.

Sulphate of lime 0.813

" * No. 6. Three feet below the river beach [from pit, lower part of Z>,
half a mile distant from preceding.']

Hygrometric moisture 5.400

By heating to low redness, it lost in addition 2.060

Carbon9,te of lime 0.535

Bi-sulphuret of iron 2.060

Sulphate of lime 0.661

Carbonate of magnesia and sulphate of alumina in traces.
Phosphate of lime as in number 1.
'' 'No. 9. See foregoing, page 465. This alone having sulphuret of iron
visible in powder, or minute crystals ;' [taken from 14 feet below the
beach, in E.']

* This specimen was not thoroughly analyzed, and therefore the contents
are reported but in part. The next (No. 3) was deemed the most important,
and a more correct specimen of this layer (Z>), and therefore to it the
examination of Prof. Shepard was especially requested, and was so directed.
It is therefore that the contents of bi-sulphuret of iron, carbonate of lime,
and sulphate of lime are not stated of No. 1 , as in No. 3. E. R.

ANALYSES OF GYPSEOUS EARTH. 473

* Carbonate of lime 2.350

Bi-sulpliuret of iron 5.821

Sulphate of lime 2.309

(Carbonate of magnesia not found.)

" 'No. 10. Several tbin layers of compressed shells, 1 to 3 inches thick"
[contained in stratum E."]

Carbonate of lime 56.00

Phosphate of lime 0.84

" No. 2. [Z>] from 4 feet lower than number 1, was examined with results
similar to 1 and 3.

' ' No. 4. [Z>] from 4 feet below beach, and half a mile from number 1 , was
found to be rich in sulphate of lime and to contain bi-sulphuret of iron.

"No. 5. [i>] 'From another spot, and has since been exposed to the
weather from last winter to June on the field where applied as manure.'
Is richer than No. 2 or 4 in sulphate of lime, but inferior to either in bi-
sulphuret of iron. It likewise affords more sulphate of alumina than any
sample examined.

" 'No. 11. The clay at 16 to 18 feet deep ;' [supposed when selected to
be the poorest part of stratum E.'\

Carbonat* of lime 1.45

" It is rich in sulphate of lime, and has traces of sulphate of alumina,
and bi-sulphuret of iron.

" It is to be kept in mind that in these analyses no account is taken of
such sized crystals of sulphate of lime as readily meet the eye, or of large
fragments of shells, the occasional presence of both which must often
essentially enhance the gypseous and calcareous contents of these samples.
The proportions in which they may occur at different depths and localities
can readily be determined, however, by the practical agriculturist. The
same may be said of the phosphatic ingredient so far as the teeth and
bones of fishes are concerned.

If we assume the average proportion of bi-sulphuret of iron in these
earths to be 2 per cent., and suppose the whole of the sulphate to become
oxydized, it would give rise to 2.722 per cent, of sulphuric acid ; to saturate
which would require 1.905 of lime, and thereby produce 4.627 per cent,
of (anhydi'ous) sulphate of lime. But 2.722 of lime would demand 3.883
per cent, of carbonate of lime in the soil. Now in the three analyses (Nos.
3, 6, and 9), made, the bi-sulphuret of iron, by average, equals 3.049 per
cent., and the carbonate of lime in the same equals but 1.478 per cent. —
a quantity too small for the saturation of the acid, even after a liberal
allowance is made for the increase of calcareous matter from the occasional
presence of large fragments of shells.

"It would therefore appear to be an obvious deduction from these inqui-
ries, that dressings of lime, and especially of calcareous bands, like No.
10, should be employed in conjunction with the green-sand soil.

" Having now replied in the best way I am able to your various inquiries,
I leave it for you to make such other practical inferences from the inform-
ation afibrded as in your more experienced judgment it may seem to
authorize — and remain, very respectfully, your obedient servant,

Charles Upiiam Shepard."

"Edmund Ruffin, Esq."

The specimens numbered above 1, 2, 3, were from one locality,

and of earth which was used as manure for clover of this year,

on marled land, with effect as great as any ever known ] and with

no certain benefit on an adjoining space (also in clover), of the

40*

474 GYPSUM THE OPERATIVE INGREDIENT.

same soil naturally, but not marled. Numbers 4, 5, and 6, were
from the pit dug in the beach, half a mile distant, apparently
similar to each other, and to the preceding specimens. All these
are of the dark stratum (i>) richest in green-sand (except the
lowest, ^), and all before rated by me as containing 50 per cent,
of the pure granules. Professor Rogers stated the same to contain
60 to 70 per cent. (See F. llegister, vol. ii., p. 750.) Even if leaving
the green-sand out of consideration, and out of the estimate of
value, there would still remain enough of active manuring princi-
ples to produce a large share (at least) of the beneficial eifects which
I have found from the use of this earth ; and I have heard of but
few other applications in Virginia, other than those made on Coggins
Point farm, and of none with different or better certain effects.
With the help of surplus carbonate of lime in the soil (furnished
by nature or by previous marling or liming), 100 bushels of this
earth, averaging in strength the ingredients of these specimens
analyzed by Professor Shepard, would furnish nearly 5 bushels of
pure sulphate of lime (gypsum) ; and 40 bushels to the acre would
furnish 2 bushels of sulphate of lime. Not one of these specimens
contained any gypsum visible to the eye ; and but one specimen
(number 9) contained any visible sulphuret of iron ; and therefore
these ingredients may be fairly supposed to be at least as abundant
in the earth dug in any considerable operation. What the green-
sand or any other ingredients may do in addition, I pretend not to
estimate. But so far as I have learned from my own experience
and all known experience of other persons, the whole operation of
this earth, when used alone, is precisely of such kind as I would
anticipate from gypsum, though' yielding more of benefit in mea-
sure and value. Nor should I therefore be understood as placing
a low estimate on the value of the effects produced. Since seeing
the effects this year, and especially since having formed the opinion
that the upper and exposed parts (most generally used formerly)
are comparatively worthless and should be avoided, I count on
much benefit being derived from this manure, and am desirous that
it shall be largely used ; as my son and partner, and the sole
director of our farming, proposes to do for the next year's growth
of clover. Still, I am now as far as ever from believing in or ex-
pecting such great and regular benefit as would be inferred to be
certain from views and statements which rest upon the authority
of the former geological surveyor of Virginia.*

«- Professor Shepard, in the above letter, asserts the identity of the gra-
nules of "green-sand," with chlorite, or green talc. The proportions of
the constituents of chlorite are far from being uniform ; though the same
kinds are usually found, in various proportions. Of these, magnesia seems
to be always present. If so, may not this be an important manuriug ele-

EOCENE GREEN-SAND MARL.

475

It may not be useless to note another point of recent resemblance
between these two manures, both" of which seem so capricious and
uncertain in operation in general. This year (1842), the applica-
tions of the green earth on the Coggins Point farm, whether made
in the beginning of the winter preceding, in March, or in the be-
ginning of summer, have acted more quickly and powerfully than
any known before. This I had ascribed to the earth being mostly
obtained from deeper excavations. But I have lately heard, from
Messrs. Hill Carter and John A. Selden, both extensive and ex-
perienced and successful users of gypsum, that they have never
before known the good effects of that manure to be so remarkable
as in all their applications of this year.

(dS) Eocene green-sand marl.

Except in the lower stratum exposed in the pit recently dug at
Evergreen, this peculiar and valuable kind of marl has not yet been
known to me in Virginia elsewhere than on and near the borders
of the Pamunkey river; though there can be but little doubt that
this or other eocene deposits are to be found elsewhere than within
the limits here stated of the now known localities. It is more than
probable that other rivers cut through and expose some of the eocene
as well as miocene deposits; and that deep diggings would reach
them also in the intervening high lands. The Pamunkey eocene
•formution is seen first, or exposed most south-eastward, at North-
bury in New Kent county ; and it is found (either as marl or gyp-
seous earth) on nearly every farm above, to South Wales, in Hano-
ver, the farm of Mr. William F. Wickham, just below the junction
of the North Anna and South Anna rivers, and on North Wales,
the farm of Mr. Williams Carter, across the Pamunkey, in Caroline
county. This distance in a tlraight line is about 22 miles ; and

ment of our green-sand earth, as well as that of New Jersey ? Cleaveland
gives the following contents of three different kinds of chlorite, ascertained
by different chemists:

Chlorite — analyzed, by | Vauqueliii. | Klaproth.

Ilocpfnor.

100 parts consisted of

Silex

26.

53.

41.15

Alumina

18.5

12.

G.13

Magnesia ....

8.

3.5

39.47

Lime

0.

2.5

1.5

Oxide of iron ....

43.

17.

10.15

Muriate of soda and potash

2.

0.

0.

Water

2.

11.
99.

1.5

99.50

99.90

Vauquelin found a specimen of comr

Qon talc to

contain 27 ]

aer cent, of

476 GREEN-SAND OR GYPSEOUS MARL.

the very winding course of the Pamunkey serves to make the ex-
posure of the bed of marl show an average width of three or more
miles. Throughout this area, it is found in great abundance at
numerous points — though of great variety of appearance and of
value at different elevations, and in very different degrees of access,
or ease of working.

This marl everywhere has its calcareous portion (which is usually
small in comparison to good miocene marls) intermixed with a
large proportion of green-sand. The calcareous earth varies from
10 to 40 per cent, at different diggings, or different layers at the
same locality; and the green-sand perhaps from 10 to 30 per cent,
as estimated by the eye. In some places, the one ingredient pre-
dominates in quantity, and elsewhere the other. No one specimen
has been found rich in both of these ingredients.

There are various and very different kinds of earth, if considered
in reference to their chemical constitution and qualities, and values
as manure, which together make up this extensive area and great
depth of the eocene formation ; and all of which varieties, however
different, have in common been deemed and termed marl by the
people of the neighbourhood. That all these various earths belong
to the same eocene formation is evident from the fossil remains, or
from other as certain proofs where there are no such remains visi-
ble. The principal and most notable of these different earths will
be here described.

The most extensive exposure of calcareous marl, which I will
designate as L, (and embraces beds 4 and 5 in the profile view,
which will be hereafter given), is along the river for five or six miles
in a straight course, above and below Newcastle ferry; and a very
much longer course, if following the crooked course of the Pamun-
key. This marl is more than 24 fo#fc thick at Clifton, the farm of
Mr. J. W. Tomlin, next below Newcastle ferry. From that locality,
it becomes thinner in the extensions both up and down the river.
At two miles above the thickest part, it gradually thins out to
nothing, in Marlbourne farm (my own property) ; and before reach-
ing the nearest outline of Marlbourne, this marl (L) is barely 2 feet
thick, and not worth for use the cost of removing the overlying
drift or other earth. This marl and all the other accompanying
beds, are inclined; the "dip being towards the east or south-east.
The ancient flood proceeding from the north-west had washed away
the highest raised western parts of all these beds, and reduced them
to their now nearly horizontal surface; and this ancient "denu-
ding" action is the cause of this marl, and the other beds, succes-
sively thinning out at the surface as proceeding up the river.

This most extensively exposed body of marl is of four principal
kinds, without noticing some less important differences. The lower
6 or 7 feet of its thickness (x) and which includes all of 4 in the

GREEN-SAND OR GYPSEOUS MARL. 477

figure, except the black line at bottom), is the richest in calcareous
matter, and much the best as manure. This is mostly of compact
and uniform earthy texture and appearance — of dark gray colour,
with a greenish tint in some cases. The shelly matter, for the
greater part, is finely reduced, the fragments being generally so
small as not to be obvious to the sight. But few shells, mostly of
the harder gray kinds, remain entire ; and of these, the saddle oyster
furnishes nearly all of the perfect and still very hard specimens.
Near to the bottom of this layer the marl is somewhat softer and
poorer, and yet the entire though very soft shells are there nu-
merous. This marl (x^ contains from 35 to more than 40 per cent,
of carbonate of lime, on an average.

Above this richer part (x), the marl (marked 5 in the figure) is
softer, and in some degree admits the slow penetration of water, to
which the other marl (x) is a perfect barrier. In other respects
this (y) appears to the eye very similar, and not less rich in calca-
reous matter than that below. But in fact it does not contain more
than proportions varying from 30 to as little as 11 per cent., and
usually becoming poorer as nearer to the top of this layer. This
marl (?/), more generally than the richer below, I have found to
contain finely divided sulphuret (or bi-sulphuret) of iron, as does
the gypseous earth of James river, and also the gypseous earth of
Pamunkey. This combination of sulphur and iron, when exposed
to air, changes gradually to sulphate of iron (copperas) ; and this
last, and the carbonate of lime of the marl, decompose each other,
and one of the new products is sulphate of lime (gypsum), in place
of proportional quantities of the decomposed copperas and shelly
matter. This process has doubtless been proceeding for ages in the
bed, though very slowly for want of air ; and has served to remove
much of the formerly existing shelly matter — which was first thus
changed to sulphate of lime, and this soluble substance was then
mostly carried off by the slowly percolating water. This decom-
position and subsequent removal of the lime also served to make
pervious the before compact and impervious marl, and thus per-
mitted more easily the progress of further decomposition and re-
moval of the former calcareous portion. However much of the
produced gypsum has been thus slowly dissolved and removed, there
is still a considerable proportion remaining. Thus, this part (^),
especially, not only contains a notable proportion of gypsum before
formed by this process, and not yet removed in solution by the
slowly percolating water — but theijp is also generally present (in y
especially), more of material, in the as yet undecomposed sulphuret,
to form more gypsum hereafter. I infer that this mode of conver-
sion of part of the carbonate to sulphate of lime has served to more
or less diminish, and in some layers to remove entirely, the consi-
derable amount of carbonate of lime formerly contained. More

478 GREEN-SAND OR GYPSEOUS MARL.

carbonate must be so changed to sulphate of lime, after any 'marl
which still contains sulphuret of iron, is applied as manure. The
exposure to air (and attraction of oxygen) will soon convert the
yet remaining sulphuret to sulphate of iron ; and this will imme-
diately act on the carbonate of lime, in contact, and so form sul-
phate of lime. This proportion of gypsum, either ready formed, or
soon to be formed, making altogether from 2 to 6 per cent, of the
marl, is one of the main sources of the early (but, as I anticipate,
transient) fertilizing effects of this and other varieties, which are
poor in calcareous matter. The long continued action of the sul-
phuret of iron (which seems to be still generally present, and may
be inferred to have been universal at first in all the beds) is suffi-
cient to account for the partial or total disappearance of shells, and
of carbonate of lime, in nearly all these layers of the one great
eocene bed of marl and gypseous earth, both of Pamunkey and
James river.

A third variety (u) exists but in few places, and on the northern
side of the river. It is the highest of this whole calcareous bed —
is dry and yellowish (being nearly or quite destitute of green-sand
and organic colouring matter), and though as rich in carbonate of
lime as the average of the whole stratum (and richer than all y), it
is much inferior in fertilizing effects, at least for some years, and as
long as they have been separately observed. It may be inferred
that this light-coloured marl is not only without the potash (which
green-sand contains in small proportion), but also without gypsum ;
and, like nearly all miocene marls, acts only by its carbonate of
lime.

A fourth variety (;s) is the universal thin bottom layer of this
calcareous stratum (and below x — represented by the broad black
line in the figure), which forms a continuous layer of separate
stony lumps, like a pavement, and varying from 6 to 15 inches
thick. These stony masses contain 60 per cent, or more of car-
bonate of lime. Being difficult to dig, and to raise, this layer is
usually left by most marlers. On account of its greater richness, I
deem it the most valuable for its quantity. In a few years after
being ploughed under the soil, most of these lumps are softened
enough to crumble.

These several layers of this one general calcareous stratum con-
stitute the marl mostly used in latter years, by the marling farmers
of this neighbourhood. My own use has embraced all these varie-
ties, but was mostly of the moije compact earthy marl (x), as that
was in greatest quantity.

Another bed of rich calcareous marl (M,) is exposed for the few
miles of the most western extremity of the general eocene forma-
tion, in the farms of South Wales in Hanover, and North Wales
in Caroline county, and extending nearly to the lowest part of the

OLIVE EARTH. 479

granite range, wliieh makes the falls of this and other rivers. This
marl is darker coloured (nearly black in the bed), and apparently
richer in green-sand than the former kinds, and also nearly as rich
as the best (x) in carbonate of lime. I found of this bed, in dif-
ferent specimens selected by myself from the pits of Messrs. Wm.
F. Wickham and Williams Carter, proportions varying from 32.50
to 44 per cent. This kind also contains some finely divided and
diffused sulphuret of iron; and consequently, gypsum, if not al-
ready present (as I infer is always the case), must be formed from
the changes of the sulphuret after the application of the marl.

This bed, though lying the highest, where exposed, in its pre-
sent level and elevation, is the lowest in order of all the different
beds of this great eocene formation. Below it is a bed of gravelly
sand and rounded pebbles, without any appearance of fossil remains,
or marine deposition.

For some 12 miles (if in a straight line, but following the much
longer course of the river), and stretching from the final thinning
out of the marl (x, or 4), in Marlbourne farm to the first appear-
ance (of M, or 1) in South Wales, the whole interval is filled by
different layers and kinds of green or gypseous earth. The general
appearance is much like that of Coggins Point, before described,
but generally containing some little admixture of shells. For a
considerable part of this exposure, this gypseous earth is as desti-
tute of shelly matter, and as deficient in other fertilizing matters,
as I have found, or supposed, to be the upper or exposed parts of
the James river gypseous earth. In some layers there is enough
of shelly matter to make from 2 to 5 per cent, of the mass. Also
there are some bands of a few inches thick only, quite rich in shells.
In other places, there is no carbonate of lime ] and although some
gypsum and less potash must be present (as in general of all these
eocene beds), this poorer earth (miscalled '^ marl") has been found,
when used as manure, of little effect, and less profit..

Overlying all the exposed upper marl and green earth of this
whole eocene formation (and also extending south-eastward over
the nearest miocene) is an unconformable layer of variable but
always '^mall thickness of what is here known as " olive earth,''
from its greenish brown colour. (It is designated by the broad
irregular band o, o, in the figure.) It varies from a few inches to
4 feet of thickness — is not uniform in texture — but usually very
adhesive (as found wet in the bed), and difficult to remove. My
observations have satisfied me that this earth was formerly marl,
or rather a mixture of all the different layers of marl and green
earth now below, which after being washed up by the violent cur-
rent of the ancient denuding flood, was, during a cessation of the
greatest violence of the current, deposited over the whole before
denuded and then bare surface. Subsequently, the violence of tho

480 OLIVE EARTH.

current was renewed, and with it were brought and deposited the
layers of drifted pebbles, sandy gravel first, and next sand, which
now overlie all the olive earth and eocene formation. This lower
sandy gravel is ferruginous, and everywhere supplies ferruginous
spring-water, and probably the impregnation being partly in the
form of sulphate of iron. Both the sulphates of iron and of
alumina are sometimes perceptible to the sight and taste, in these
strata. The slowly oozing spring-water thus bringing either of
these salts of sulphuric acid, must gradually decompose any carbo-
nate of lime in contact. And hence, the higher deposit of what is
now olive earth, being permeable by water, has had all its former
carbonate of lime changed to gypsum, and this, in solution, mostly
removed by the water passing off. If these suppositions are correct,
the olive earth ought still to contain all that it did formerly, when
it was marl, except the carbonate of lime ; and with some increase
of sulphate of lime. Hence, this earth ought to have more or less
of fertilizing value — and enough to be worth using, especially as
its very laborious excavation and removal have always to be
effected, for the purpose of reaching the marl below. !^ut it was
universally believed that the olive earth was useless; and it was
put to no use, not only by those farmers who had good marl below,
but by others who encountered all the labour of uncovering, and
removing this sticky and troublesome layer, to reach merely the
gypseous earth below, probably worth no more than the olive earth,
except for its very small proportion of carbonate of lime. While
I drew marl from other land to my present form, the distance was
too great for me to try this olive earth as manure. But since I
have (very lately) discovered good marl, of workable thickness, on
Marlbourne farm, I have carried out all the overlying olive earth,
though it is more sandy here than is usually found. I had begun
this course before having heard of any useful effect of such appli-
cation. But since (in the summer of 1852), I have learned very
remarkable effects of other (and probably much richer) olive earth,
as tried by two neighbouring farmers, Messrs. Henry Jones and
John Beale. The most accurate and conclusive of these trials
(though all were very beneficial) was an application of this earth
alone, 400 bushels to the acre, on stiff and poor (long exhausted)
land. The application was made for the corn crop of 1850, and
produced not much, if any, perceptible effect. The benefit was
much greater, though still small, on the succeeding crop of wheat.
But of the next following clover, which I saw in May and June,
1852, the growth was more luxuriant than any on the richest other
land; and the effect of the olive earth alone, was greater on the
clover (as compared with adjacent ground without this or other
dressing) than from marl, with its unquestionable accompaniment
of gypsum, or other manure elsewhere on similar lands of this

GYPSEOUS EARTH OP PAMUNKEY. 481

neiglibourhood. Still, I believe that gypsum is the principal ma*
nuring principle — and that these wonderful effects will therefore
be confined mostly to clover (or other leguminous plants), during
its temporary action. The remains of bones and teeth also are
more numerous in this olive earth (immediately above the marl)
than anywhere lower; and hence this layer, apparently, is better
supplied with phosphate of lime — -a manure of very great and
peculiar value for other crops, and especially for wheat.

All these different beds, or thinner layers and varieties, of this
great eocene formation, except the high yellowish layer («), con*
tain cither a considerable or a large proportion of green-sand — •
and of course some little potash — which, as chemists inform us, is
a universal though small proportion of green-sand. Also, from
the very general indications either of white and tasteless efflores-
cence, or of manifest sulphuret of iron, or both, I infer that gypsum
also is a very general, if not a universal ingredient, to some amount.

Until within the few latter years, all the various layers and
qualities of the whole eocene formation, were confounded in com*
mon understanding and parlance, through this neighbourhood, under
the one name of " marl.'^ The green or gypseous earth was used
indiscriminately with the calcareous marl, by those proprietors who
had both exposed by the same excavations, without their looking
for or observing any difference of operation. The existence of this
strange error, and its general continuance (in this neighbourhood)
for eight or ten years, can only be accounted for by the following
circumstances : The two different layers were generally obtained in
the same excavations, and were more or less mixed in use — and
never kept entirely separate for experiment : The soils (of Pamun-
key low-ground) being mostly or nearly neutral, did not exhibit
much effect from marl on the earlier grain crops, (as acid and much
worse soils would have done — ) and when clover followed, the great
benefit which that crop always received from the large quantity of
gypsum in the green earth, even if with very little admixture of
calcareous matter, would make nearly as much show on that crop
as the marl alone. And before these early atid transient benefits
of gypsum would be ended, perhaps another slight dressing of
marl would be applied, or some other treatment which would help
to conceal the respective operations of these different manuring
earths.

But more lately, no farmer of this neighbourhood has deemed
the green earth worth applying as manure, if he could obtain
marl. Still, some who have easy access to thd former only, have
begun its use within the last few years, and so far, they report
encouraging results — which the gypsum, with very little shelly
matter, can furnish for a few years. And so inveterate is esta-
blished error, that some other farmers, even to this day, would
41

483 INUTILITY OF GREEN-SAND AS MANURE.

prefer a green-sand marl, however poor in carbonate of lime, to
any miocene (or other) marl thrice as rich in the latter and all-im-
portant ingredient, but destitute of the misunderstood and there-
fore highly prized green-sand. This erroneous view is the result
(and the only abiding result to agriculture known to me) of the
statements and instructions of the late geological surveyor, and his
exaggerated and unmodified panegyrics on the asserted value of
green-sand as manure — the " discovery of which in Virginia was
claimed as his own, and cried up as the greatest possible benefit to
agricultural improvement. Yet still (and long before that gentle-
man had either written about green-sand, or seen so much as a hand-
specimen), my own use of this earth alone, far exceeded in quan-
tity all other applications in Virginia, and has only since been ex-
ceeded in amount by the later applications of my son and successor
on Coggins Point farm ; and no user of it has yet been rewarded
for his labour, from any possible effects of the green-sand alone.
All the appreciable and known benefits have been produced by the
gypsum, or the carbonate of lime, or both, used generally in con-
junction. Where neither of these aids was present, either in
the manure or the soil, I have never yet heard of a profitable use,
in Virginia, of the earth having no manuring ingredient save the
green-sand. Still, I do not deny that it may be valuable — and
should be much gratified and greatly profited as a farmer, to be
assured that such value and profit as have been claimed for this
earth are indeed available. In my own extensive trials of the
green earth of James river, and the still more extended and more
beneficial recent applications on my former property, by the present
proprietor, there has been no efi'ect found that could be ascribed to
green-sand, or to its potash — or to anything but the gypsum, and
that only on either marled or naturally calcareous or neutral soil.
And in the much more extended practice of my neighbours on the
Pamunkey, who have largely used this earth as marl, but almost
always more or less intermixed with some carbonate of lime, there
is nothing in the known efi"ects which would go to contradict the
opinions on this subject which I have here concisely, and formerly
at greater length, expressed. It is important to know all the value
of this earth as manure, and to avail ourselves of it fully; but to
do that, it is essential that the true source of the beneficial opera-
tion should be known, and that the delusion produced by the
influence of scientific but undeserved authority, should end, as it
surely will, soon or late.

The occurrence of the very diflerent appearances and qualities
of this formation, as found by digging, or in the natural exposures
on the river banks, has been generally deemed altogether irregular
and subject to no rule of position. Hence it was supposed that the

ORDER OF THE PAMUNKEY BEDS. 483

finding of marl, by boring in places where the existence was not
before known, and the variety or quality of whatever could be
so reached, were matters of chance. Of course all searches for
marl, by boring, were directed by no rule except that of selecting
surfaces of low level. And this one object was mistaken, and would
often cause the concealed marl bed to be missed by borings made in
its close neighbourhood. For if in land of alluvial formation, the
ancient flood most generally had swept off all the previously exist-
ing marl, and the vacancy so made was afterwards filled by either
the succeeding drifted earth, in part, or entirely by still later allu-
vial deposits.

But if proper attention is given to the general dip of the whole
formation, and the succession of the different layers, as exposed
naturally, and nearer the surface, or to some extent in perpen-
dicular cuts and excavations, there may be found reliable indica-
tions of the position of each layer in other places. With the aid
of this guide it might be generally known, in advance of all search-
ing, and for miles of surface upon which the seeker for marl had
never trod, whether and where marl would probably be found, and
of what quality, and where there would be none worth working.

This very thick formation, or bed of many layers of different
qualities, as has been stated, has a general dip to the south-east, or
down the general course of the river. In the opposite direction,
up the river, or as proceeding north-westward, all the layers, (unless
running out earlier,) in succession, rise above the level of the river;
and consequently, each of these layers, in succession, becomes the
upper one at some locality, and is there the first and perhaps the
only one to be reached by digging. And as the ancient flood had,
by its denuding action, washed away all these raised edges of layers,
and so made a new surface approaching to horizontal, it follows
that each layer, after appearing as the highest and most accessible
at some place, thence thins out as proceeding westward, until that
layer disappears, and the next one in order, below, becomes there
the highest and most accessible layer. The figure of the following
section, though for much the greater part conjectural, will serve for
better explanation, and may serve to indicate, either as to this or
other beds and localities, how to direct searches for concealed marl,
with the best prospect of success, and to avoid the loss of useless
examinations. The supposed surface line is designed for the south-
ern side of the Pamuukey, and the eocene beds (and overlying
miocene also, in part) where exposed nearest to the river. The in-
clination of the dip, and also the perpendicular distances, are both
greatly magnified in proportion to the horizontal distance, for the
purpose of making the successive layers more distinct, and of
bringing the whole extent of surface within convenient size.

West

South Wales.
Broadneck.

Stevenson's.

Gold Hill.

Summer Hill.
Dabney's Ferry.

Spring Garden.
Marlbourne.

Newcastle.
Fen-y.

Clifton.

Farmington.
Springfield.

Betreat.

Northbury.

Hampstead.

Higb lands.
East.

ORDER OF THE PAMUNKEY BEDS. 485

Explanations of pi'ojile^ or perpendicular section

a, a, Level, or surface of Pamunkey river — air-line between extremes of

section, 26 miles.

b, b, Surface of land, "second low ground" nearest to river.

1, 1, The lowest, and 8, 8, the highest bed of the whole eocene formation,
of marl and gypseous earth of various kinds.

0, 0, Layer of olive earth laying on the raised and denuded ends of lower

beds, forming the present upper surface of the eocene formation.
e, e, Sandy gravel and rounded pebbles, lying beneath the lowest eocene
bed.

1, 1, Lowest bed — rich marl, rising above river and exposed at South

Wales.

2, 2, Green or gypseous earth, without calcareous matter.

3, 3, 3, 8, Green or gypseous earth beds, with very small and variable

amounts of shells, either in thin bands, or very slight general admix-
ture. All poor as manure, and mostly not worth using. More shelly,
and richer otherwise, where highest and next to

4, Lower and richer part of the upper calcareous beds of the eocene,

(designated as L and x and y), in foregoing general description,
stony layer (z) at bottom.

5, Upper and softer part of the good eocene marl — poorer in calcareous

matter, and containing bi-sulphuret of iron, generally.

6, Green or gypseous earth, with some calcareous matter — or poor marl.

7, Green earth, destitute of calcareous matter, and worthless as manure.

8, Green earth, with some calcareous matter, or poor marl.

9, Miocene marl of Hampstead, lying immediately on the eocene bed.

10, Ordinary miocene marl, lying higher than the Hampstead bed.

The various beds of this formation, in regard to extent, succes-
sion, and particular qualities (as before intimated), are represented
mostly upon conjecture. Even of the actual exposures above the
water-line (a, a), I have seen but a small extent ; and, of course,
as to what is below the depth of actual excavations and the river,
all rests on conjecture, or reasoning from analogy. Neither is it
designed to be conveyed that the different strata or layers preserve
the regular proportions of thickness, as represented in the figure.
On the contrary, it is more usual for each different layer to vary
much in thickness, in a long stretch of distance, and in some cases
to " run out,'' and come to an end. Still, after making due allow-
ance for all such sources of uncertainty and error, this figure, and
the judicious deductions which every reader may make for the fea-
tures of his own locality, may be of great use in searching for the
richest layers of marl, and still more in avoiding such labour when
certain to be disappointed. According to this conjectural section,
if it were possible and useful to sink a shaft, or boring, deep enough
on the most eastern point exhibited, every separate layer or bed
would be reached in regular succession. It might be as low as 300
feet or more — but at some depth it is probable that the rich marl
(M.) now only known (and accessible) at the north-western extreme,
could be reached under the south-eastern, or more than twenty miles
41*

48G SULPIIUllET OF IRON IN aVI'SEOUS EARTIf.

distant. But omitting such merely speculative matters, there are
practicable and profitable operations to bo based on the knowledge
of the succession and dip of the strata. Thus, when the existence
of rich marl is known in any point, and its depth, it is almost cer-
tain that it will thin out towards the north-west, and either thicken,
or maintain its then thickness, as proceeding south-eastward. On
land north-westward of the disappearance (at top) of a rich bed,
(as 4), and however near, it would be in vain to search for the like.
The boring for any practicable depth on most of the river land of
Marlbourne '(for example) could reach only the poor beds exposed
at the surface for some ten miles, including the beds marked 3 and
2, perhaps, also. But on land south-eastward, and near to the
surface exposure of any rich marl, it might be expected to reach
the like at some greater depth. The lowest eocene marl which I
reached by sinking the pit for examination 25 feet below tide on
Evergreen (described p. 462), and which must have been near to
the bottom of the lowest bed, exhibited the same peculiar appear-
ance, and some of the peculiar fossils, which are also to be seen in
(M) the lowest of the Pamunkey layers, and at an exposure thirty
miles distant. In no other localities had I seen either the same
appearance of marl, or the same rare shells, as some of both common
to these places only. In the much deeper pit sunk for examina-
tion on Coggins Point (p. 465), though the rising of water at 49
feet prevented deeper digging, the fossils then reached indicated
the near approach to the same lowest marl found at less depth at
Evergreen, and exposed much above the river at North and South
Wales. Hence, it may be inferred that this lowest and very pe-
culiar bed of this great formation, as well as the formation generally,
is continuous under all this broad surface of territory.

Many specimens of the marl and gypseous earth of the Pamun-
key beds, were made partially red hot, for the purpose of showing
whether sulphureous fumes were so disengaged, as was stated on a
foregoing page (460) to be the case with most specimens tried of
the James river gypseous earth. This result w^as obtained in all
of sundry trials of the gypseous earth (3) below the marl (4) — in
the marl at South Wales (M), and in some cases, but not generally,
of the richer marl 4. In the still higher and poorer marl (5),
which I lately have excavated extensively in the Clifton bank, the
Bulphureous fumes were obtained in every trial. A specimen of
marl from Pipingtree, and many specimens of the gypseous earth
(upper part of 3) from Newcastle ferry, Newcastle farm, and from
Marlbourne, all gave out these fumes. Sundry other specimens of
calcareous green-sand marl which were thus treated, yielded no
fumes. The latter results were found in specimens from the several
diggings at Newcastle (both sides of the river), and at Mr. (i. ^V.
Bassett's bank, Farmington. It may not be useless to repeat here,

. GREEN-SAND SUPPOSED IN MIOCENE MAULS. 487

and thus to place in connexion with these results, that all the dark
green or blackish earth (Z>) of Coggins Point gave out those suf-
focating fumes, and also the gray clay (JE^) below, and most power-
fully— and that no such product was found from any of the very
shelly bands. Thus it would seem that most generally the non-
calcareous earths (or nearly non-calcareous) gave out fumes, and
the calcareous not. But exceptions were found to both. And of
the New Jersey green-sands, containing no carbonate of lime, six
specimens were tried at red heat, of the beds most esteemed for
manure, and not the slightest disengagement of such fumes was
produced.*

This extrication of sulphureous fumes by the first beginning of red
heat, is a sure indication of the presence of sulphuret (or bi-sul-
phuret) of iron. And wherever this exists in contact with marl, and
with the access of air and water, first the sulphate of iron will be
formed, and next this salt will decompose as much carbonate of lime
as its quantity will act upon, and so form gypsum. Therefore,
wherever the sulphuret of iron is present in marl, or is put in con-
tact with it, in soil, it is certain that, in the same proportion, carbo-
nate of lime wijl be decomposed, and sulphate of lime formed. Of
course no addition of other gypsum is needed, or could act if
Applied, on land recently supplied, in marl, with enough sulphuret
of iron, even if the partial previous decomposition of the latter
had not already formed gypsum in the bed of marl, as is usually
the case.

Of Green-sand as an ingredient of Miocene Marls.

In a previous page (439), the presence of green-sand in mioceno
marls, as an important and general ingredient, was denied ; and the
subject then pjtssed by, with the promise of its being subsequently
resumed. Having treated of the gypseous earth and of eocene
green-sand marls, of both of which green-sand forms large and im-
portant proportions, it is now most appropriate to inquire into the
alleged extent and operation of this substance in miocene marls.

In 1834, Professor William B. Rogers Tthen and long before a
resident of lower Virginia) announced that ne had discovered green-
sand to be a considerable ingredient of nearly all the many ordinary
miocene marls which he had examined either in place or by speci-
mens ; and from which observations he inferred the same admix-

* The New Jersey "marls" thus tried were selected by the writer from
the pits of Josiah Heritage and Thomas Bee of Gloucester, and Henry
Allen, Allen Wallace, J. Riley, and J. Cauley, Salem county. The same
results were found as to the poorer (or less valued) overlying strata of
Heritage, R. Dickenson, J, Cauley, and also of the barren green clay or sub-
soil. See all described in my report, on the New Jersey green-sand earths,
Farmers' Register, vol. x. p. 429,

488 PROFESSOR ROGERS' DISCOVERS.

ture to be general as to other miocene marls ; and that the propor-
tions of green-sand so contained were large enough to form useful
additions to, and in some cases the most valuable portion of the
manuring ingredients of such marls (Farmers' Register, vol. ii., p.
129). At a later time, he added to like general opinions and state-
ments the following : ^^ In some of these deposits [marl beds in the
vicinity of Williamsburg], so large a proportion as 30 and in
some specimens 40 per cent, [of pure green-sand] has been found ;

- and in cuses like this, if we are to trust to the experience of New
Jersey, a very marked addition to the fertilizing power of marl
must be ascribed to the presence of this ingredient.'^ (Farmers'
Register, vol. ii., p. 747.) In a subsequent communication to the
Philosophical Society of Philadelphia in 1835, and again in the first
report of the geological survey of Virginia, the material parts of the
above statements are re-asserted, in substance, and nearly in the
same words. These statements and opinions were received, when
announced, as undoubted, and they have not since been questioned
in any publication ; nor have they since been either confirmed by
any additional proof or testimony, nor have they, in direct terms,
been modified or retracted by their author. Yet the correctness or
incorrectness of the assertion of such abundance and general diflfu-
eion of green-sand in the miocene marls of Virginia is a matter of
great interest ; and, in its bearing on the application of marl and
the rationale of its operation, of great importance to agricultural
improvement. It is certain that to this day [1842], many proprie-
tors consider that their marls are peculiarly valuable because of the
supposed large proportions of green-sand therein ; such opinions
being founded either on the publications, or, with still more confi-
dence, upon the personal examinations and verbally expressed
opinions of the former state geologist.

My own personal examinations of marls in place, and analyses of
specimens of other beds, have been very extensive ; and my atten-
tion has been given especially in regard to this point to sundry
specimens, including several of the particular bodies of marl which
it is understood that Professor Rogers had pronounced to be very
rich in green-sand — containing, say, 20 to 30 per cent, of the black
granules so called. I have found some green-sand (but generally
in very small proportion) in nearly all the specimens examined
particularly for this substance ; and believe that Professor Rogers

- was correct so far as inferring that it is a very frequent ingredient.
And for the first observation of this curious and interesting fact he
is justly entitled to the entire credit. To such extent as green-sand
is present, and according to the manner of the operation of that
earth (whatever that may be), the green-sand in the miocene marls
must be effective and useful. But whether such effect be of any
distinguishable and appreciable value, or not, depends on the quau-

EXAMINATION OP ITS WORTH. 489

tity and proportion of green-sand in the marl ; and, so far as all my
experience and observation enable me to judge, I cannot but believe
that the above stated estimates of quantities and proportions of
green-sand are greatly exaggerated, and extremely incorrect and
delusive. I do not mean to assert, and cannot be expected to prove,
the negative of the assertion of such abundance of green-sand. But,
from, all my means for arriving at conclusions, it is my confident
belief that but few of the bodies of miocene marls in Virginia con-
tain as much as 2 per cent, of green-sand — if even as much as 1 per
cent. ; and that an average proportion, throughout any considerable
digging for manure, of as much as 5 per cent, of green-sand is
extremely rare. With but a single peculiar exception, which
will be described presently, the largest proportion (estimated by the
eye) that I ever found was supposed to be 5 per cent. ; and that
was in a very peculiar marl, found at Coggins Point farm and else-
where in that neighbourhood, or rather a loose calcareous sand,
which forms the overlying layer of a compact blue marl. This sand
contains only about 20 per cent, of finely divided shelly matter, and
the whole mass would appear, to slight observation, similar to, and
as poor and as loose, as the deep sands of the roads through a sandy
country. But few persons would have used this sand for manure,
or would have dignified it by the name of marl. However, the
ease with which it could be worked, and the necessity for removing
it to uncover the better marl below, induced me to carry out and
apply it as a second dressing to an adjacent part of a field which
had been just before marled from the richer blue layer. The efiects
were so marked, and so superior to the single marling, that I was
ready to believe that the green-sand caused the diff"erence. The
loose calcareous sand mentioned at page 443, which one of my'
neighbours supposed (from its good effects) to be rich in calcareous
earth, is precisely like mine in general appearance, and in position
in the bed ; and appears to have a like unusually large proportion
of green-sand, which no doubt served to produce some small part
of the benefit which was ascribed wholly to the carbonate of lime.
This peculiar deposit furnishes the only cases known to me of any
ordinary miocene marl (if this loose sand can be so termed) being
rich enough in green-sand for the benefit from the latter to be
known. And even this benefit would not have been distinguished
or suspected, but that the poverty of the earth in calcareous matter
required it to be applied very heavily. The much thicker body of
compact marl, lying under this poor calcareous sand, contains (by
supposition) not so much as 2 per cent, of green-sand.

But it is true, that when attention was not particularly directed
to green-sand, proportions not exceeding 5 or G per cent, might
have escaped the notice of one who had handled and examined
the specimens of marl, or who even analyzed them, merely with a

400 TESTIMONY IN OPPOSITION.

view to their proportions of calcareous matter. But proportions
so large as 40, 30, or even 20 per cent, of green-sand could not
thus escape even careless and superficial observation ', for even the
smallest of these proportions would give a very manifest greenish
or gray tint to any otherwise light-coloured marl. Knowing the
great uncertainty of the guessings at proportions of green-sand
naturally intermixed with marl or other earth, I did not rely on
them except as to the absence of any very large proportion. For
more accurate testing, the clayey parts were washed off in water;
in others the calcareous parts were also removed by weak acid.
And for still better means of judging by comparison, I mixed toge-
ther, in different and known proportions, measured quantities of
light-coloured marl (such as are all those about Williamsburg), and
pure green-sand prepared by washing some obtained from the
richest beds in New Jersey. And of such artificial compounds,
examined by the eye both when dry and in powder, and wet, and also
after being again dried in mass, the admixture of green-sand, even
when as small as 10 per cent., was obviously more abundant than
in the miocene marls reputed to be among the richest in green-sand.
Under these circumstances, without denying the possible existence
of such cases, it is proper to wait for and to require further proofs
of assertions of such large proportions as 20 to 40 per cent.

But there is much better support for my position, of the general
scarcity of green-sand in miocene marls, than any proofs, positive
or negative, that I can adduce, presented by Prof. Rogers himself,
in his ^' Report of the Progress of the Geological Survey" for 1837.
lie therein gives a tabular statement of 148 specimens selected by
his assistants, and their analyses made under his own direction. It
is to be presumed that so many specimens, and thus obtained, must
present a fair and correct average of general quality of the marls
of the region in which they were found ; or at least that their con-
tents would not be too little favourable to the geologist's preconceiv-
ed opinions, or assertions. The specimens were from eighteen coun-
ties, viz. : Lancaster, Westmoreland, Richmond, Northumberland,
King G-eorge, Mathews, Middlesex, Gloucester, King and Queen,
King William, Essex, Isle of Wight, Nansemond, Elizabeth City,
Surry, Prince George, James City, and Warwick. Of these 148
specimens, of one only (S. Downing' s, Lancaster) is the quantity
or proportion of green-sand stated with any approach to precision.
This is said (no doubt by guess) to contain " 10 or 12 per cent, of
green-sand,'^ and only 17 per cent, of carbonate of lime. Of five
others, the green-sand would seem to be in notable quantities, but
as no numbers or proportions are named, it may be inferred that
the proportions were deemed less than the one just stated. These
five are described as follows, in regard to this ingredient : Calla-
han's, Lancaster, "large grains of green-sand in considerable quan-

TESTIMONY IN OPPOSITION. 491

tity;" Gloucester Town, " richly specked with green-sand;" Saun-
ders', Isle of Wight (one only of three strata), "considerable
green-sand/' Stith's, Surry, "quite richly specked with green-
sand/' A. C. Jones's, Surry, and at Kingsmill, James City, " in-
termixed with green-sand." Now what proportions these descrip-
tions designate, it is not for me to determine ; but 3 or 4 per cent.,
at most, would abundantly serve to meet all their requisitions.
There are also 7 other of the specimens named marked in less de-
grees by the presence of this ingredient, and which are described in
this respect in such phrases as these : containing " a little green-
sand" — "specked with green-sand" — "quite perceptibly specked
with green-sand" — " tinged with green-sand" — and " slightly inter-
mixed with green-sand." There remain of the list 135 other speci-
mens, of which 48 are stated to contain of " green-sand a trace"
(by which term chemists understand a proportion so small that its
presence is barely certain), and of the other 87 specimens no green-
sand is mentioned, and therefore it may be inferred that not even
" a trace" could be found.

If this list of marls and statements of their fertilizing contents
had been presented by the author distinctly as a designed refutation
of his previously and repeatedly published assertions of the frequent
abun^nce and general presence in useful quantity of green-sand in
miocene marls, nothing could have been more to the purpose, or
more conclusive.

Nevertheless, few and rare as may be the cases in which the value
and beneficial effects of miocene marls are increased in any consi-
derable degree by the presence of green-sand, or of any other in-
gredient than carbonate of lime, it is important that such auxiliary
fertilizing matters should be searched for, and their absence or pre-
sence known. The great value and uniform fertilizing efi'ects of
carbonate of lime will be the most highly appreciated by those
farmers who understand and estimate them separately and alone ;
without confounding the operation of that manuring earth with
those of any other intermixed and unknown substances, no matter
what increase of benefit such intermixture may produce in particu-
lar cases.

Some years after the publication of the first edition of this Re-
port (as originally made to the State Board of Agriculture of Vir-
ginia, and published, with other reports, by order of the legisla-
t»re), I learned that a particular bed of marl, worked at Ilampstead
in New Kent, and more lately found and now worked both at Oak
Spring and Liberty Hall, in King William county, furnished an
exception to the general rule above asserted, of the absence of any
large proportion of green-sand in miocene marl. This particular

492 PECULIAR MIOCENE MARL.

bed has been found (by boring) on both sides of the Pamunkey
river, near to and in the same general range with the eocene bed,
and within a mile of two different excavations of eocene marl, or
gypseous earth, in different directions. Further, this Hanipstead
marl contains apparently as much green-sand as the neighbouring
eocene bed ; and there is no obvious difference in the texture, co-
lour, or general appearance of the two kinds. When I first visited
this locality (May, 1842), the digging had been suspended, and the
pits were full of water ; so that no marl or shells could be seen in
the bed. My examinations therefore were limited to heaps of the
marl which remained unspread upon the field. I was surprised to
find all of the few shells which met my eye in this imperfect view,
of species such as were unknown to me, and which I had not seen
in any other marl. But this did not induce me to suspect that
the formation was not eocene, as I was not then acquainted with
many eocene shells. Subsequently, however, by more full exami-
nation, and aided by the scientific knowledge of my friend M.
Tuomey, Esq., whom I induced to visit with me this singular de-
posit, I learned that the shells, so far as recognised, were miocene ;
though mostly not known in any other of the miocene beds in Vir-
ginia— of which, sundry exposures, with numerous different shells,
are within a few miles of the Hampstead bed. There are three
shells only, of some 22 species, which I found here, known to me
also in the other miocene marls of Virginia.*

This bed is underlaid by the ordinary eocene of the neighbour-
hood. Suspecting this to be the fact in advance of any proof, I
procured an excavation to be sunk much lower than any had been
done before ; and, without any obvious change of general appearance
and texture, the eocene marl was reached — as was made evident
by the finding of perfect shells of the ostrea sellopformis.

From all the circumstances it would seem that the earthy mate-
rials of this miocene formation had been mainly derived from the
earlier formed and close adjacent eocene bed below, and which
spreads out to the westward ; and that while some flood had torn
up, swept along, and suspended for a time, and then deposited, this
fine green earth for the matrix, that the peculiar conditions permit-
ted the existence, with a few exceptions only, of shell-fish not belong-
ing to the ordinary miocene. The supposed position of this peculiar
miocene is represented (at 9) in the annexed profile of all the
strata.

This peculiar deposit, and this alone so far as known to me, would
accord with the cases asserted by Professor Rogers, of the frequent
and general occurrence of green-sand in large proportions, in ordi-
nary miocene marls. But even this case afforded no support to his

* There three are cardita granulata^ an astarte, and one other.

IIAMPSTEAD BEDS. 493

assertion, when it was published. This bed is of peculiar character,
in this respect. No other similar marl is yet known. It was every-
where concealed by its depth, and was found only by boring. The
discovery of the marl itself did not occur until long after Professor
Rogers had published these assertions ; and it was much later still,
before it was even suspected that it belonged to the miocene forma-
tion. Therefore, however conveniently the peculiar character of
this marl might have been used, if known earlier, as at least one
evidence for Professor Rogers's assertions — as the facts are, it affords
to them, as made, not the slightest support.

THE END.

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[Plough J Loom and Anvil.

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121 Main Street, Riclimond, Va.

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\_Southern Literari/ Messenger.

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J. W. RANDOLPH, of Richmond, Virginia, has published a
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letter and in the spirit, for they all tend to the introduction of
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of economy and humanity — economy in the management of the farm
or plantation — and humanity in providing for the comfort and health
of the slaves, as well as stock.

It contains a chapter explanatory of the manager's duty — shows
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[^American Farmer.

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Decisions of cases in Virginia, by the High Court of Chancery,
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discusses at large the plans for the abolition of negro slavery. While
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" I have had occasion to use Mr. Matthews' Guide to Commission-
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while attending the settlement of accounts before the Commissioner."

The following table of contents may be acceptable to our legal read-
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Chapter I. Of the origin of Commissioners in Chancery, their ap-

121 Main Street, Richmond, Va.

pointment, the reference of accounts to them, and the proceedings
thereupon. — Chap. II. Of fiduciaries generally, and the settlement of
their accounts by Commissioners in Chancery. — Chap. III. Of Guar-
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the Commiseioner's Office, and herein : — Of References and Reports ;
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Principles on which Guardians' account should be stated ; How to
state the account of one who is in name an executor, but is in fact a
guardian or trustee ; How to ascertain value of life estate or annuity ;
Table of longevity; Adjournment by Commissioner; Report and Ex-
ceptions; Review of Report. — Chap. V. Of surcharge and falsifica-
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Of means for compelling debtor to discover and surrender his estate.
Chap. IX. Of fees of Commissioner in Chancery. — Chap. X. Of de-
scents and distributions. — Chap. XI. Of the payment of debts accord-
ing to their priority. — Chap. XII. For preventing commission of crimes.
By the Code of Virginia, Chapter 201, Section 1, Commissioners
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chapter is a summary of the proceedings on peace warrant, &c. Every
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VIRGINIA REPORT on the Resolutions of '98-'99, concern-
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[Richmond Republican.

10 J.W, Randolph^ Bookseller,

A comprehensive DESCRIPTION OF YIEGINIA and the
DISTRICT OF COLUMBIA, containing a copious collection of
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miscellaneous information, chiefly from original sources, by Joseph
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by W. H. Brockenbrough, formerly Librarian at the University of
Virginia, and afterwards Judge of the United States Court in Florida.

The above Book contains 636 printed pages, 8vo., bound in strong
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money or stamps.

< ♦ • • >

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money by sending their orders to J. W. RANDOLPH.

Rare old works bought and sold.

HANDSOME BINDING.— In J. W. RANDOLPH'S window,
at No. 121 Main Street, may be seen a BIBLE, bound in his estab-
lishment by one of his workmen, which in point of neatness of finish,
beauty of style and durability, cannot be excelled. Our citizens
would do well to bear these facts in mind, and have their Books bound
at home, instead of sending them to the Northern abolitionists.

[^Republican r

4 ♦ » ♦ »■■

COUNTRY MERCHANTS, Teachers and others, can buy on the
best terms Standard, School and Miscellaneous Books, Stationery, &c.

BLANK BOOKS made to order, and BINDING done in any
Cfuantity and style.

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UNIVERSITY OF CALIFORNIA LIBRARY
BERKELEY
Return to desk from which borrowed
_J^«book is DUE on the last date stamped below.

=? 195210

REC'D LD

Af? 1 1S57

WAR 8 1982

BE& CIS. MAY 0 G Az

LD 21-95m-n,'50 (2877816)476

YB 16459

LD-9 80m 11/80 (Bay View)

678992

UNIVERSITY OF CALIFORNIA LIBRARY

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